p53-BINDING POLYPEPTIDES AND POLYNUCLEOTIDES ENCODING SAME

Abstract: The invention provides mammalian polypeptides which bind wild-type and/or mutant mammalian p53 proteins, polynucleotides encoding such polypeptides, screening assays for drug development employing such polypeptides and polynucleotides, immunological and other reagents for diagnostic, therapeutic, and research applications.

Description: p53-BINDING POLYPEPTIDES AND POLYNUCLEOTIDES ENCODING SAME TECHNICAL FIELD The invention provides novel polypeptides which are associated with cellular proliferation and neoplastic transformation, polynucleotides encoding such polypeptides, antibodies which are reactive with such polypeptides, polynucleotide hybridization probes and PCR amplification probes for detecting polynucleotides which encode such novel polypeptides, transgenes which encode such polypeptides, homologous targeting constructs that encode such polypeptides and/or homologously integrate in or near endogenous genes encoding such polypeptides, nonhuman transgenic animals which comprise functionally disrupted endogenous genes that normally encode such polypeptides, and transgenic nonhuman animals which comprise transgenes encoding such polypeptides. The invention also provides methods for detecting neoplastic or preneoplastic conditions in a patient, methods for treating neoplastic and preneoplastic conditions, methods for screening for antineoplastic agents and carcinogens, methods for diagnostic staging of neoplasia, methods for producing cell proliferation control proteins for use as research or diagnostic reagents, methods for producing antibodies reactive with the novel polypeptides, and methods for producing transgenic nonhuman animals expressing the novel polypeptides encoded by a transgene. BACKGROUND The proliferation of normal cells is thought to be regulated by growth-promoting proto-oncogenes counterbalanced by growth-constraining tumor-suppressor genes. Mutations that potentiate the activities of proto-oncogenes create the oncogenes that force the growth of neoplastic cells. Conversely, genetic lesions that inactivate tumor suppressor genes, generally through mutation(s) that lead to a cell being homozygous for the inactivated tumor suppressor allele, can liberate the cell from the normal replicative constraints imposed by these genes. Often, an inactivated tumor suppressor gene (e.g., p53, RB, DCC, NF-1 ) in combination with the formation of an activated oncogene (i.e., a proto-oncogene containing an activating structural or regulatory mutation) can yield a neoplastic cell capable of essentially unconstrained growth (i.e., a transformed cell) . While different types of genetic alterations may all lead to altered expression or function of cell-growth regulatory genes and to abnormal growth, it is generally believed that more than one event is required to lead to neoplastic transformation of a normal cell to a malignant one (Land et al. (1983) Nature 304: 596; Weinberg RA (1989) Cancer Res. 49 : 3713. The precise molecular pathways and secondary changes leading to malignant transformation for most cell types are not clear. A number of cases have been reported in which altered expression or activity of some proteins, such as the tumor suppressor gene protein p53 , appears to be causally linked to the aberrant cell proliferation and growth control observed in neoplastic cells. Recent advances in molecular genetics have uncovered a number of genes that exhibit structural alterations in clonal human tumors and are therefore presumed to play important roles in carcinogenesis. A variety of cancer- related genes have been classified in the broad categories of either dominantly acting oncogenes or recessive tumor suppressor genes (reviewed in Weinberg RA (1989) Cancer Res. 49: 3713 and Marshall CJ (1991) Cell 64: 313) . The distinction between these two categories has been somewhat blurred by the discovery of genes that can, under appropriate assay conditions, act as either oncogenes or tumor suppressor genes. This phenomenon is exemplified by the p53 gene, whose wild-type form has tumor suppressive properties and some of whose mutants exhibit dominant oncogene-like properties (Lane DP and Benchimol S (1990) Genes Dev. 4 . : 1; Michalovitz et al. (1990) Cell 62: 671; Eliyahu et al. (1989) Proc. Natl. Acad. Sci. (U.S.A.) 86: 8763; Finlay et al. (1989) Cell 57: 1083; Lane DP (1992) Nature 358: 15) . The p53 gene product is a nuclear phosphoprotein involved in the control of cell proliferation, and mutations in the p53 gene are commonly found to be associated with diverse type of human cancer (Levine et al. (1991) Nature 351: 453) . The p53 phosphoprotein associates with the SV40 large T antigen, adenovirus Elb protein, and human papillomavirus E6 protein, each of which are proteins implicated in the oncogenic activity of their respective viruses. These associations between p53 and viral oncoproteins may repress the activity of wild-type p53 by targeting it for rapid degradation or by sequestering it in inactive complexes (Scheffner et al. (1991) Cell 63: 1129; Oren et al. (1981) Mol. Cell. Biol. 1: 101; Yew PR and Berk AJ (1992) Nature 357: 82) . Wild-type p53 exhibits DNA-binding activity (Kern et al. (1991) Science 252: 1708) and transcriptional activation properties (Fields S and Jang SK (1990) Science 249: 1046; Raycroft et al. (1990) Science 249: 1049; Bargonetti et al. (1991) Cell 65: 1083; Agoff et al. (1993) Science 259: 84) . Point mutated forms of p53 found associated with transformed cells have been observed to have lost the sequence-specific DNA binding function (Kern et al. (1991) op.cit; Bargonetti et al. (1991) op.cit. : El-Deiry et al. (1992) Nature Genetics 1 : 45) . Moreover, many of the mutant p53 proteins can act as dominant negatives to inhibit this activity of wild-type p53. Interestingly, some of the viral-encoded oncoproteins (e.g., SV40 large T antigen) also inhibit the DNA-binding activity of p53 apparently as a consequence of forming complexes with the p53 protein (Bargonetti et al. (1991) op.cit. ) . A rat protein that co-immunoprecipitates with the p53 protein has been identified as the rat homologue of the mouse MDM2 protein (Barak Y and Oren M (1992) EMBO J. 11: 2115) . The MDM2 gene was originally identified as a dominant transforming oncogene present on mouse double minute chromosomes; the human homologue of MDM2 has been cloned and the human MDM2 protein binds p53 (Fakharzadeh et al. (1991) EMBO J. 10: 1565; Oliner et al. (1992) Nature 358: 80) . Transgenic animals harboring a functionally disrupted p53 gene (Donehower et al. (1992) Nature 356: 215) has been described for use in carcinogen screening assays, among others. Cell Proliferation Control and Neoplasia Many pathological conditions result, at least in part, from aberrant control of cell proliferation, differentiation, and/or apoptosis. For example, neoplasia is characterized by a clonally derived cell population which has a diminished capacity for responding to normal cell proliferation control signals. Oncogenic transformation of cells leads to a number of changes in cellular metabolism, physiology, and morphology. One characteristic alteration of oncogenically transformed cells is a loss of responsiveness to constraints on cell proliferation and differentiation normally imposed by the appropriate expression of cell growth regulatory genes. Despite progress in developing a more defined model of the molecular mechanisms underlying the transformed phenotype and neoplasia, few significant therapeutic methods applicable to treating cancer beyond conventional chemotherapy have resulted. The observation that aberrant p53 function is frequently correlated with neoplasia supports a model wherein p53 protein is involved in control of cell proliferation, and may be involved in one or more signalling pathways that transduce growth regulatory signals. If such a model were correct, p53 and biological macromolecules (i.e., proteins) that specifically interact with p53 would be candidate targets for therapeutic manipulation. For example and not limitation, if a hypothetical protein X bound to p53 forming a complex and thereby stimulated neoplastic growth of cells, agents that would selectively inhibit formation of the protein X : p53 complex or otherwise modulate p53 activity may be candidate antineoplastic agents. The identification of proteins that interact with p53 protein provide a basis for screening assays for identifying agents that specifically interfere with the intermolecular association between p53 protein and such interacting proteins. These screening assays can be used to identify candidate p53 modulating agents that can serve as candidate therapeutic agents. Such p53 modulating agents can provide novel chemotherapeutic agents for treatment of neoplasia, cell proliferative conditions, arthritis, inflammation, autoimmune diseases, and the like. The present invention fulfills these and other needs. Thus there exists a need in the art for identification and isolation of novel genes associated with neoplasia, methods for employing those genes for diagnostic and therapeutic applications, and polynucleotide constructs and transgenic animals having modified variants of such genes. The present invention fulfills these and other needs. The references discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention. SUMMARY OF THE INVENTION The present invention provides several novel methods and compositions for modulating p53 activities and for screening for modulators of p53 activities. These methods utilize polynucleotide sequences encoding p53-interacting proteins and polynucleotides which are substantially identical to naturally-occurring polynucleotide sequences (e.g., cDNA or genomic gene) that encode such p53-interacting proteins. In one aspect of the invention, p53-interacting polypeptides and compositions thereof are provided. In one embodiment, p53-interacting polypeptides comprise polypeptide sequences which are substantially identical to a sequence shown in Fig. 1A-1D, designated WBP1, or Fig. 2, designated p53UBC, or a cognate gene sequence in another species. Polynucleotide sequences encoding p53-interacting polypeptides are provided. The characteristics of the cloned sequences are given, including the nucleotide and predicted amino acid sequences in Figs. 1A-1D or Figs. 2. Polynucleotides comprising these sequences can serve as templates for the recombinant expression of quantities of p53- interacting polypeptide polypeptides, such as human WBP1 and human p53UBC. Polynucleotides comprising these sequences can also serve as probes for nucleic acid hybridization to detect the transcription rate and mRNA abundance of p53-interacting polypeptide mRNA (e.g., WBP1 and p53UBC) in individual lymphocytes (or other cell types) by in situ hybridization, and in specific cell populations by Northern blot analysis and/or by in situ hybridization (Alwine et al.(1977) Proc. Natl. Acad. Sci. U.S.A. 74: 5350) and/or PCR amplification and/or LCR detection. Such recombinant polypeptides and nucleic acid hybridization probes have utility for in vitro screening methods for therapeutic agents (e.g., antineoplastic agents) , for diagnosis and treatment of neoplastic or preneoplastic pathological conditions and genetic diseases, and for forensic identification of human individuals, among other uses apparent to those of skill in the art. In one embodiment, candidate therapeutic agents are identified by their ability to block the binding of a p53- interacting polypeptide to a p53 polypeptide. The p53 polypeptide preferably is a full-length mature p53 protein and frequently is phosphorylated, although the phosphorylation state of individual p53 species can be variable. Typically, the p53 polypeptide comprises an amino acid sequence identical to a wild-type p53 protein sequence, although mutant p53 polypeptides are sometimes used if the mutant p53 polypeptide binds to the p53-interacting polypeptide under control assay conditions (e.g., physiological conditions) . Agents are tested for their ability to alter binding between a p53 polypeptide and a p53-interacting polypeptide under suitable assay binding conditions. One means for detecting binding of a p53 polypeptide to a p53-interacting polypeptide is to immobilize the p53 polypeptide, such as by covalent or noncovalent chemical linkage to a solid support, and to contact the immobilized p53 polypeptide with a p53-interacting polypeptide that has been labeled with a detectable marker (e.g., by incorporation of radiolabeled amino acid, by epitope tagging and reporting with a fluorescent-labelled anti-epitope tag antibody, and the like) . Such contacting is typically performed in aqueous conditions which permit binding of a p53 polypeptide to a p53-interacting polypeptide comprising a functional p53 binding site. Binding of the labeled p53- interacting polypeptide to the immobilized p53 is measured by determining the extent to which the labeled p53-interacting polypeptide is immobilized as a result of a specific binding interaction. Such specific binding may be reversible, or may be optionally irreversible if a cross-linking agent is added in appropriate experimental conditions. Alternatively, the p53 polypeptide may be labelled and the p53-interacting polypeptide immobilized. In one variation, the binding assay is performed with soluble (i.e., non-immobilized) p53 and p53- binding polypeptides and the resultant bound complexes (p53 :p53-binding polypeptide) are separated from unbound p53 and p53-binding polypeptides, and the bound complexes are quantitated. Agents that inhibit or augment the formation of bound complexes as compared to a control binding reaction lacking agent are thereby identified as p53-modulating agents and are candidate therapeutic agents. In one variation, the binding assay is performed in vivo in a cell, such as a yeast cell (e.g., Saccharomvces) . and agents which inhibit intermolecular binding between a p53 protein and a p53-interacting polypeptide are identified as p53-modulating agents. Frequently, the n vivo screening assay is a yeast two-hybrid system wherein the yeast cells express: (1) a first fusion protein comprising p53 and a first transcriptional regulatory protein sequence (e.g., GAL4 activation domain) , (2) a second fusion protein comprising a p53-interacting polypeptide and a second transcriptional regulatory protein sequence (e.g., GAL4 DNA-binding domain), and (3) a reporter gene (e.g., β-galactosidase) which is transcribed when an intermolecular complex comprising the first fusion protein and the second fusion protein is formed. If a functional p53 :p53 -inter acting polypeptide complex forms, such as in a control assay lacking agent, the cell expresses the reporter gene which can be detected. Agents which inhibit or augment formation of functional p53 :p53-interacting polypeptide complexes (and thus reporter gene expression) are thereby identified as p53-modulating agents. The invention also provides antisense polynucleotides complementary to polynucleotides encoding p53- interacting polypeptide sequences. Such antisense polynucleotides are employed to inhibit transcription and/or translation of the p53-interacting polypeptide mRNA species and thereby effect a reduction in the amount of the respective p53-interacting polypeptide in a cell (e.g., a lymphocytic leukemia cell of a patient) . Such antisense polynucleotides can function as p53-modulating agents by inhibiting the formation of p53-interacting polypeptides required for modulation of p53 function by the p53-interacting polypeptide. In a variation of the invention, polynucleotides of the invention are employed for diagnosis of pathological conditions or genetic disease that involve neoplasia of other medical conditions related to p53 function, and more specifically conditions and diseases that involve alterations in the structure or abundance of a p53-interacting polypeptide, such as WBP1 or p53UBC. The invention also provides antibodies which bind to Lyar with an affinity of about at least 1 x 10 7 M _1 and which lack specific high affinity binding for a p53-interacting polypeptide, such as WBP1 or p53UBC . Such antibodies can be used as diagnostic reagents to identify cells exhibiting altered p53 function (e.g., preneoplastic or neoplastic cells) in a cellular sample from a patient (e.g., a lymphocyte sample, a solid tissue biopsy) as being cells which contain an increased amount of p53-interacting polypeptide as compared to non-neoplastic cells of the same cell type(s) . Frequently, anti-p5 -interacting polypeptide antibodies are included as diagnostic reagents for immunohistopathology staining of cellular samples in situ. Additionally, anti-p53-interacting polypeptide antibodies may be used therapeutically by targeted delivery to neoplastic cells (e.g., by cationization or by liposome/immunoliposome delivery) . The invention also provides p53-interacting polypeptide polynucleotide probes for diagnosis of disease states (e.g., neoplaώia or preneoplasia) by detection of a p53-interacting polypeptide mRNA or rearrangements or amplification of the p53-interacting polypeptide gene in cells explanted from a patient, or detection of a pathognomonic p53- interacting polypeptide allele (e.g., by RFLP or allele- specific PCR analysis) . Typically, the detection will be by in situ hybridization using a labeled (e.g., 32 P, 35 S, 14 C, 3 H, fluorescent, biotinylated, digoxigeninylated) p53-interacting polypeptide polynucleotide, although Northern blotting, dot blotting, or solution hybridization on bulk RNA or poly A + RNA isolated from a cell sample may be used, as may PCR amplification using p53-interacting polypeptide-specific primers. Cells which contain an altered amount of p53- interacting polypeptide mRNA as compared to non-neoplastic cells of the same cell type(s) will be identified as candidate diseased cells. Similarly, the detection of pathognomonic rearrangements or amplification of the p53-interacting polypeptide gene locus or closely linked loci in a cell sample will identify the presence of a pathological condition or a predisposition to developing a pathological condition (e.g., cancer, genetic disease) . The polynucleotide probes are also used for forensic identification of individuals, such as for paternity testing or identification of criminal suspects or unknown decedents. The present invention also provides a method for diagnosing a disease (e.g., neoplasia) in a human patient, wherein a diagnostic assay (e.g., immunohistochemical staining of fixed cells by an antibody that specifically binds human p53-interacting polypeptide) is used to determine if a predetermined pathognomonic concentration of p53-interacting polypeptide or its encoding mRNA is present in a biological sample from a human patient; if the assay indicates the presence of p53-interacting polypeptide or its encoding mRNA outside of the normal range (e.g., beyond the predetermined pathognomonic concentration) , the patient is diagnosed as having a disease condition or predisposition. The invention also provides therapeutic agents which inhibit neoplasia or apoptosis by modulating p53 function by inhibiting or augmenting formation of complexes of p53 :p53- interacting polypeptide, such agents can be used as pharmaceuticals. Such pharmaceuticals will be used to treat a variety of human and veterinary diseases, such as: reperfusion injury, myocardial infarction, stroke, traumatic brain injury, neurodegenerative diseases, aging, ischemia, toxemia, infection, AIDS, hepatitis, and the like. The invention also provides methods for identifying polypeptide sequences which bind to a p53-interacting polypeptide. By definition, one member of the set of interacting proteins is p53. For example, a yeast two-hybrid screening system can be used for identifying polypeptide sequences that bind to WBP1 or p53UBC. Yeast two-hybrid systems wherein one GAL4 fusion protein comprises a p53- interacting polypeptide sequence, typically a full-length of near full-length WBP1 or p53UBC polypeptide sequence (e.g., a polypeptide sequence of Figs. 1A-D or 2) , and the other GAL4 fusion protein comprises a cDNA library member can be used to identify cDNAs encoding proteins which interact with the p53- interacting polypeptide, can be screened according to the general method of Chien et al. (1991) op.cit. Alternatively, an E. coli/BCCP interactive screening system (Germino et al. (1993) Proc. Natl. Acad. Sci. (U.S.A.) 90: 933; Guarente L (1993) Proc. Natl. Acad. Sci. (U.S.A.) 90: 1639, incorporated herein by reference) can be used to identify interacting protein sequences. Also, an expression library, such as a λgtll cDNA expression library, can be screened with a labelled p53-interacting polypeptide to identify cDNAs encoding polypeptides which specifically bind to the p53-interacting polypeptide. For these procedures, cDNA libraries usually comprise mammalian cDNA populations, typically human, mouse, or rat, and may represent cDNA produced from RNA of one cell type, tissue, or organ and one or more developmental stage. Specific binding for screening cDNA expression libraries is usually provided by including one or more blocking agent (e.g., albumin, nonfat dry milk solids, etc.) prior to and/or concomitant with contacting the labeled p53-interacting polypeptide (and/or labeled anti-p53-interacting polypeptide antibody) . BRIEF DESCRIPTION OF THE FIGURES Figs. 1A-1D show the nucleotide sequence and deduced amino acid sequence of human WBP1. Fig. 2 shows the nucleotide sequence and deduced amino acid sequence of human p53UBC. The translational frame is shown as the deduced amino acid sequence of the p53UBC protein. Definitions Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described. For purposes of the present invention, the following terms are defined below. As used herein, the twenty conventional amino acids and their abbreviations follow conventional usage (Immunology - A Synthesis, 2nd Edition, E.S. Golub and D.R. Gren, Eds., Sinauer Associates, Sunderland, Massachusetts (1991) , which is incorporated herein by reference) . Stereoisomers (e.g., D- amino acids) of the twenty conventional amino acids, unnatural amino acids such as ,α-disubstituted amino acids, N-alkyl amino acids, lactic acid, and other unconventional amino acids may also be suitable components for polypeptides of the present invention. Examples of unconventional amino acids include: 4-hydroxyproline, 7-carboxyglutamate, e-N,N,N- trimethyllysine, e-N-acetyllysine, O-phosphoserine, N- acetylserine, N-formylmethionine, 3-methylhistidine, 5- hydroxylysine, ω-N-methylarginine, and other similar amino acids and i ino acids (e.g., 4-hydroxyproline) . In the polypeptide notation used herein, the lefthand direction is the amino terminal direction and the righthand direction is the carboxy-terminal direction, in accordance with standard usage and convention. Similarly, unless specified otherwise, the lefthand end of single-stranded polynucleotide sequences is the 5' end; the lefthand direction of double-stranded polynucleotide sequences is referred to as the 5 1 direction. The direction of 5 ' to 3 ' addition of nascent RNA transcripts is referred to as the transcription direction; sequence regions on the DNA strand having the same sequence as the RNA and which are 5' to the 5 ' end of the RNA transcript are referred to as "upstream sequences"; sequence regions on the DNA strand having the same sequence as the RNA and which are 3 • to the 3 ' end of the RNA transcript are referred to as "downstream sequences". The term "naturally-occurring" as used herein as applied to an object refers to the fact that an object can be found in nature. For example, a polypeptide or polynucleotide sequence that is present in an organism (including viruses) that can be isolated from a source in nature and which has not been intentionally modified by man in the laboratory is naturally-occurring. The term "corresponds to" is used herein to mean that a polynucleotide sequence is homologous (i.e., is identical, not strictly evolutionarily related) to all or a portion of a reference polynucleotide sequence, or that a polypeptide sequence is identical to a reference polypeptide sequence. In contradistinction, the term "complementary to" is used herein to mean that the complementary sequence is homologous to all or a portion of a reference polynucleotide sequence. For illustration, the nucleotide sequence "TATAC" corresponds to a reference sequence "TATAC" and is complementary to a reference sequence "GTATA" . The following terms are used to describe the sequence relationships between two or more polynucleotides: "reference sequence", "comparison window", "sequence identity", "percentage of sequence identity", and "substantial identity" . A "reference sequence" is a defined sequence used as a basis for a sequence comparison; a reference sequence may be a subset of a larger sequence, for example, as a segment of a full-length cDNA or gene sequence given in a sequence listing, such as a polynucleotide sequence of Figs. 1A-1D or Fig. 2, or may comprise a complete cDNA or gene sequence. Generally, a reference sequence is at least 20 nucleotides in length, frequently at least 25 nucleotides in length, and often at least 50 nucleotides in length. Since two polynucleotides may each (1) comprise a sequence (i.e., a portion of the complete polynucleotide sequence) that is similar between the two polynucleotides, and (2) may further comprise a sequence that is divergent between the two polynucleotides, sequence comparisons between two (or more) polynucleotides are typically performed by comparing sequences of the two polynucleotides over a "comparison window" to identify and compare local regions of sequence similarity. A "comparison window", as used herein, refers to a conceptual segment of at least 20 contiguous nucleotide positions wherein a polynucleotide sequence may be compared to a reference sequence of at least 20 contiguous nucleotides and wherein the portion of the polynucleotide sequence in the comparison window may comprise additions or deletions (i.e., gaps) of 20 percent or less as compared to the reference sequence (which does not comprise additions or deletions) for optimal alignment of the two sequences. Optimal alignment of sequences for aligning a comparison window may be conducted by the local homology algorithm of Smith and Waterman (1981) Adv. Ap l. Math. 2_: 482, by the homology alignment algorithm of Needleman and Wunsch (1970) J. Mol. Biol. 48: 443, by the search for similarity method of Pearson and Lipman (1988) Proc. Natl. Acad. Sci. (U.S.A.) 85: 2444, by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package Release 7.0, Genetics Computer Group, 575 Science Dr. , Madison, WI) , or by inspection, and the best alignment (i.e., resulting in the highest percentage of homology over the comparison window) generated by the various methods is selected. The term "sequence identity" means that two polynucleotide sequences are identical (i.e., on a nucleotide-by-nucleotide basis) over the window of comparison. The term "percentage of sequence identity" is calculated by comparing two optimally aligned sequences over the window of comparison, determining the number of positions at which the identical nucleic acid base (e.g., A, T, C, G, U, or I) occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the window of comparison (i.e., the window size), and multiplying the result by 100 to yield the percentage of sequence identity. The terms "substantial identity" as used herein denotes a characteristic of a polynucleotide sequence, wherein the polynucleotide comprises a sequence that has at least 85 percent sequence identity, preferably at least 90 to 95 percent sequence identity, more usually at least 99 percent sequence identity as compared to a reference sequence over a comparison window of at least 20 nucleotide positions, frequently over a window of at least 25-50 nucleotides, wherein the percentage of sequence identity is calculated by comparing the reference sequence to the polynucleotide sequence which may include deletions or additions which total 20 percent or less of the reference sequence over the window of comparison. The reference sequence may be a subset of a larger sequence, for example, as a segment of the human WBP1 polynucleotide sequence shown in Figs. 1A-1D or the human p53UBC polynucleotide sequence shown in Fig. 2. As applied to polypeptides, the term "substantial identity" means that two peptide sequences, when optimally aligned, such as by the programs GAP or BESTFIT using default gap weights, share at least 80 percent sequence identity, preferably at least 90 percent sequence identity, more preferably at least 95 percent sequence identity or more (e.g., 99 percent sequence identity) . Preferably, residue positions which are not identical differ by conservative amino acid substitutions. Conservative amino acid substitutions refer to the interchangeability of residues having similar side chains. For example, a group of amino acids having aliphatic side chains is glycine, alanine, valine, leucine, and isoleucine; a group of amino acids having aliphatic- hydroxyl side chains is serine and threonine; a group of amino acids having amide-containing side chains is asparagine and glutamine; a group of amino acids having aromatic side chains is phenylalanine, tyrosine, and tryptophan; a group of amino acids having basic side chains is lysine, arginine, and histidine; and a group of amino acids having sulfur-containing side chains is cysteine and methionine. Preferred conservative amino acids substitution groups are: valine- leucine-isoleucine, phenylalanine-tyrosine, lysine-arginine, alanine-valine, and asparagine-glutamine. The term "WBP1 native protein" and "p53-_7.BC native protein" as used herein refers to a naturally-occurring WBP1 or p53UBC polypeptide corresponding to the deduced amino acid sequence shown in Figs. 1A-1D or 2, respectively, or corresponding to the deduced amino acid sequence of a WBP1 or p53UBC full-length cDNA produced from a mammalian mRNA sample, such as a human mRNA sample. Also for example, a native WBP1 or p53UBC protein present in naturally-occurring human cells which express the WBP1 or p53UBC gene are considered full- length proteins. The term "fragment" as used herein refers to a polypeptide that has an amino-terminal and/or carboxy-terminal deletion, but where the remaining amino acid sequence is identical to the corresponding positions in the naturally- occurring (e.g., mature protein) sequence deduced, for example, from a full-length cDNA sequence (e.g., the cDNA sequence shown in Figs. 1A-1D or 2) . Fragments typically are at least 14 amino acids long, preferably at least 20 amino acids long, usually at least 50 amino acids long or longer. The term "analog" as used herein refers to polypeptides which are comprised of a segment of at least 25 amino acids that has substantial identity to a portion of the deduced amino acid sequence shown in Figs. 1A-1D or Fig. 2, and which has at least one of the following properties: (1) specific binding to a p53 polypeptide (e.g., human p53 phosphoprotein) under suitable binding conditions, or (2) ability to modulate p53 activity when expressed in a mammalian cell (e.g., mimic a p53 mutant phenotype) . Typically, analog polypeptides comprise a conservative amino acid substitution (or addition or deletion) with respect to the naturally- occurring sequence. Analogs typically are at least 20 amino acids long, preferably at least 50 amino acids long or longer, most usually being as long as full-length naturally-occurring p53-interacting polypeptide (e.g., as shown in Figs. 1A-1D or 2) . Some p53-interacting polypeptide analogs may lack biological activity but may still be employed for various uses, such as for raising antibodies to p53-interacting polypeptide epitopes, as an immunological reagent to detect and/or purify -p53-interacting polypeptide antibodies by affinity chromatography, or as a competitive or noncompetitive agonist, antagonist, or partial agonist of native p53- interacting polypeptide function. The term "polypeptide" is used herein as a generic term to refer to native protein, fragments, or analogs of a polypeptide sequence. Hence, native protein, fragments, and analogs are species of the polypeptide genus. Preferred p53- interacting polypeptides include: the human full-length protein comprising the polypeptide sequence shown in Figs. 1A- ID or 2, or polypeptides consisting essentially of a sequence shown in Table III or Table IV. The term "cognate" as used herein refers to a gene sequence that is evolutionarily and functionally related between species. For example but not limitation, in the human genome, the human CD4 gene is the cognate gene to the mouse CD4 gene, since the sequences and structures of these two genes indicate that they are highly homologous and both genes encode a protein which functions in signaling T cell activation through MHC class II-restricted antigen recognition. Thus, the cognate murine gene to the human WBPl gene is the murine gene which encodes an expressed protein which has the greatest degree of sequence identity to the human WBPl protein and which exhibits an expression pattern similar to that of the human WBPl gene. Preferred cognate WBPl and p53UBC genes are: rat WBPl or p53UBC, rabbit WBPl or p53UBC, canine WBPl or p53UBC, nonhuman primate WBPl or p53UBC , porcine WBPl or p53UBC , bovine WBPl or p53UBC, murine WBPl or p53UBC , and hamster WBPl or p53UBC . The term "modulation of p53 " is used herein to refer to the capacity to either enhance or inhibit a functional property of p53 (e.g., DNA-binding activity, transcriptional enhancement activity, cell replication phenotype) ; such enhancement or inhibition may be contingent on the occurrence of a specific event, such as activation of a signal transduction pathway, and/or may be manifest only is particular cell types. The altered ability of p53 to modulate transcriptional enhancement or inhibition may affect the inducible transcription of a gene or may effect the basal level transcription of a gene, or both. The term "agent" is used herein to denote a chemical compound, a mixture of chemical compounds, a biological macromolecule, or an extract made from biological materials such as bacteria, plants, fungi, or animal (particularly mammalian) cells or tissues. Agents are evaluated for potential activity as p53 modulatory agents (e.g., antineoplastic agents, cytotoxic agents, cell proliferation- promoting agents, and the like) by inclusion in screening assays described hereinbelow. The term "candidate agent" is used herein to refer to an agent which is identified by one or more screening method(s) of the invention as a putative p53 modulatory agent. Some candidate p53 modulatory agents may have therapeutic potential as drugs for human use. As used herein, the terms "label" or "labeled" refers to incorporation of a detectable marker, e.g. , by incorporation of a radiolabeled amino acid or attachment to a polypeptide of biotinyl moieties that can be detected by marked avidin (e.g., streptavidin containing a fluorescent marker or enzymatic activity that can be detected by optical or colorimetric methods) . Various methods of labeling polypeptides and glycoproteins are known in the art and may be used. Examples of labels for polypeptides include, but are not limited to, the following: radioisotopes (e.g., 3 H, 1 C, 35 S, 125 I, 131 I) , fluorescent labels (e.g., FITC, rhodamine, lanthanide phosphors), enzymatic labels (e.g., horseradish peroxidase, β-galactosidase, luciferase, alkaline phosphatase) , biotinyl groups, predetermined polypeptide epitopes recognized by a secondary reporter (e.g., leucine zipper pair sequences, binding sites for secondary antibodies, metal binding domains, epitope tags) . In some embodiments, labels are attached by spacer arms of various lengths to reduce potential steric hindrance. As used herein, "substantially pure" means an object species is the predominant species present (i.e., on a molar basis it is more abundant than any other individual macromolecular species in the composition) , and preferably a substantially purified fraction is a composition wherein the object species comprises at least about 50 percent (on a molar basis) of all macromolecular species present. Generally, a substantially pure composition will comprise more than about 80 to 90 percent of all macromolecular species present in the composition. Most preferably, the object species is purified to essential homogeneity (contaminant species cannot be detected in the composition by conventional detection methods) wherein the composition consists essentially of a single macromolecular species. Solvent species, small molecules (<500 Daltons) , and elemental ion species are not considered macromolecular species. As used herein the terms "pathognomonic concentration", "pathognomonic amount", and "pathognomonic staining pattern" refer to a concentration, amount, or localization pattern, respectively, of a p53-interacting polypeptide or mRNA in a sample, that indicates the presence of a disease condition or a predisposition to developing a disease, such as neoplasia or senescence. A pathognomonic amount is an amount of a p53-interacting polypeptide or encoding mRNA in a cell or cellular sample that falls outside the range of normal clinical values that is established by prospective and/or retrospective statistical clinical studies. Generally, an individual having a disease (e.g., neoplasia) will exhibit an amount of a p53-interacting polypeptide or mRNA in a cell or tissue sample that is significantly higher or lower than the range of concentrations that characterize normal, undiseased individuals; typically the pathognomonic concentration is at least about one standard deviation above or below the mean normal value, more usually it is at least about two standard deviations or more above or below the mean normal value. However, essentially all clinical diagnostic tests produce some percentage of false positives and false negatives. The sensitivity and selectivity of the diagnostic assay must be sufficient to satisfy the diagnostic objective and any relevant regulatory requirements. In general, the diagnostic methods of the invention are used to identify individuals as disease candidates, providing an additional parameter in a differential diagnosis of disease made by a competent health professional. DETAILED DESCRIPTION Generally, the nomenclature used hereafter and the laboratory procedures in cell culture, molecular genetics, and nucleic acid chemistry and hybridization described below are those well known and commonly employed in the art. Standard techniques are used for recombinant nucleic acid methods, polynucleotide synthesis, and microbial culture and transformation (e.g., electroporation, lipofection) . Generally enzymatic reactions and purification steps are performed according to the manufacturer's specifications. The techniques and procedures are generally performed according to conventional methods in the art and various general references (see, generally. Sambrook et al. Molecular Cloning: A Laboratory Manual, 2d ed. (1989) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., which is incorporated herein by reference) which are provided throughout this document. The procedures therein are believed to be well known in the art and are provided for the convenience of the reader. All the information contained therein is incorporated herein by reference. Oligonucleotides can be synthesized on an Applied Bio Systems oligonucleotide synthesizer according to specifications provided by the manufacturer. Methods for PCR amplification are described in the art (PCR Technology: Principles and Applications for DNA Amplification ed. HA Erlich, Freeman Press, New York, NY (1992) ; PCR Protocols: A Guide to Methods and Applications, eds. Innis, Gelfland, Snisky, and White, Academic Press, San Diego, CA (1990); Mattila et al. (1991) Nucleic Acids Res. 19: 4967; Eckert, K.A. and Kunkel, T.A. (1991) PCR Methods and Applications 1 : 17; PCR, eds. McPherson, Quirkes, and Taylor, IRL Press, Oxford; and U.S. Patent 4,683,202, which are incorporated herein by reference) . Identification of p53-Interacting Polypeptide Sequences Polypeptide sequences which interact with mammalian p53 polypeptide sequences may be identified by a variety of methods, including but not limited to: (1) co- immunoprecipitation of proteins associated with p53 in extracts of mammalian cells or cell nuclei, (2) screening of an expression library using a two-hybrid reporter system, such as a yeast two-hybrid system (Chien et al. (1991) Proc. Natl. Acad. Sci. (U.S.A.) 88: 9578; Zervos et al. (1993) Cell 72: 223) , and (3) screening cDNA expression libraries with labeled p53 protein (or p53 protein which is subsequently detected with a labelled antibody) (Ayer et al. (1993) Cell 72: 211). Alternatively, an E. coli/BCCP interactive screening system (Germino et al. (1993) Proc. Natl. Acad. Sci. (U.S.A.) 90: 933; Guarente L (1993) Proc. Natl. Acad. Sci. (U.S.A.) 90: 1639, incorporated herein by reference) can be used to identify interacting protein sequences. For proteins isolated by co-immunoprecipitation with p53 using and -p53 antibody, generally the isolated p53- interacting polypeptide is purified to homogeneity and sequenced by Edman degradation. From the amino acid sequence(s) thus generated, degenerate oligonucleotide probes encoding the amino acid sequence(s) are produced and labelled for screening a cDNA or geno ic library. For polypeptide sequences identified by two-hybrid screening or cDNA library screening with p53 protein, the polynucleotide sequences encoding the p53-interacting polypeptide sequence are isolated and sequenced (e.g., by Sanger dideoxy sequencing) , and the correct deduced amino acid sequence is determined. For exemplification, the human WBPl and p53UBC polynucleotide and deduced polypeptide sequences were isolated by screening a two-hybrid yeast expression system for polynucleotides encoding polypeptide sequences that bind to human a p53 fusion protein (see. Experimental Examples, infra) . The invention also provides methods for identifying polypeptide sequences which bind to a p53-interacting polypeptide. For example, polynucleotides encoding polypeptide sequences that bind to WBPl or p53UBC can be identified by these methods. By definition, one member of each set of interacting proteins is p53 . For example, a yeast two-hybrid screening system can be used to screen a mammalian (e.g., human) cDNA bank for identifying cDNA species which encode polypeptide sequences that bind to WBPl or p53UBC, and will identify clones encoding p53 (wild-type) if such p53 clones are represented in the clone bank. Cloning of WBPl and p53UBC Polynucleotides Genomic or cDNA clones encoding WBPl or p53UBC conveniently may be isolated from clone libraries (e.g., available from Clontech, Palo Alto, CA) using hybridization probes designed on the basis of the nucleotide sequences shown in Figs. 1A-1D and Fig. 2 and using conventional hybridization screening methods (e.g., Benton WD and Davis RW (1977) Science 196: 180; Goodspeed et al. (1989) Gene 76: 1; Dunn et al. (1989) J. Biol. Chem. 264: 13057) . Where a cDNA clone is desired, clone libraries containing cDNA derived from cells expressing significant amounts of WBPl or p53UBC mRNA is preferred. Alternatively, synthetic polynucleotide sequences corresponding to all or part of the sequences shown in Figs. 1A-1D and 2 may be constructed by chemical synthesis of oligonucleotides. Additionally, polymerase chain reaction (PCR) using primers based on the sequence data disclosed in Figs. 1A-1D and 2 may be used to amplify DNA fragments from genomic DNA, mRNA pools, or from cDNA clone libraries. U.S. Patents 4,683,195 and 4,683,202 describe the PCR method. Additionally, PCR methods employing one primer that is based on the sequence data disclosed in Figs. 1A-1D or Fig. 2 and a second primer that is not based on that sequence data may be used. For example, a second primer that is homologous to or complementary to a polyadenylation segment or randomer may be used. It is apparent to one of skill in the art that nucleotide substitutions, deletions, and additions may be incorporated into the polynucleotides of the invention. Nucleotide sequence variation may result from sequence polymorphisms of various WBPl or p53UBC alleles, minor sequencing errors, and the like. However, such nucleotide substitutions, deletions, and additions should not substantially disrupt the ability of the polynucleotide to hybridize to one of the polynucleotide sequences shown in Figs. 1A-1D or 2 under hybridization conditions that are sufficiently stringent to result in specific hybridization. Specific hybridization is defined herein as the formation of hybrids between a probe polynucleotide (e.g., a polynucleotide of the invention which may include substitutions, deletion, and/or additions) and a specific target polynucleotide (e.g., a polynucleotide having a sequence shown in Figs. 1A-1D or Fig. 2) , wherein the probe preferentially hybridizes to the specific target such that, for example, a single band corresponding to WBPl or p53UBC mRNA (or bands corresponding to multiple alternative splicing products of the WBPl or p53UBC gene) can be identified on a Northern blot of RNA prepared from a suitable cell source (e.g., a cell expression WBPl or p53UBC mRNA) . Polynucleotides of the invention and recombinantly produced WBPl or p53UBC, and fragments or analogs thereof, may be prepared on the basis of the sequence data provided in Figs. 1A-1D or Fig. 2 according to methods known in the art and described in Maniatis et al., Molecular Cloning: A Laboratory Manual. 2nd Ed., (1989), Cold Spring Harbor, N.Y. and Berger and Kimmel, Methods in Enzvmology, Volume 152, Guide to Molecular Cloning Technigues (1987) , Academic Press, Inc., San Diego, CA, which are incorporated herein by reference. WBPl or p53UBC polynucleotides may be short oligonucleotides (e.g., 25-100 bases long) , such as for use as hybridization probes and PCR (or LCR) primers. WBPl or p53UBC polynucleotide sequences may also comprise part of a larger polynucleotide (e.g., a cloning vector comprising a WBPl or p53UBC clone) and may be fused, by polynucleotide linkage, in frame with another polynucleotide sequence encoding a different protein (e.g., glutathione S-transferase or β- galactosidase) for encoding expression of a fusion protein. Typically, WBPl or p53UBC polynucleotides comprise at least 25 consecutive nucleotides which are substantially identical to a naturally-occurring WBPl or p53UBC sequence (e.g., Figs. 1A-1D or Fig. 2) , more usually WBPl or p53UBC polynucleotides comprise at least 50 to 100 consecutive nucleotides which are substantially identical to a naturally-occurring WBPl or p53UBC sequence. However, it will be recognized by those of skill that the minimum length of a WBPl or p53UBC polynucleotide required for specific hybridization to a WBPl or p53UBC, respectively, target sequence will depend on several factors: G/C content, positioning of mismatched bases (if any) , degree of uniqueness of the sequence as compared to the population of target polynucleotides, and chemical nature of the polynucleotide (e.g., methylphosphonate backbone, phosphorothiolate, etc.), among others. For example but not limitation, suitable hybridization probes for detecting and/or quantifying the presence of WBPl mRNA in a sample generally comprise at least one, preferably at least two, frequently five, occasionally nine, and more preferably all of the following human WBPl sequences shown in Table I, or their complements: Table I: Selected Human WBPl Polynucleotide Sequences 5 '-GCACGAGGCGGACAGTGCGGAACTAAAGCAAATGGTTATG-3 ' 5 '-CTTCAAAAATTACCATTTTATGATTTACTGGATGAACT-3 ' 5 '-CATCAGACAACAGTCAGCGCTTTCGAGAAACCTGTTTTGC-3 ' 5 '-CACAACAAGTGCAGCAAATCAGTAGTTCCATGGATA-3 » 5 -GTACAGGTCCAGTTAAGGTTTTGTTTATCAGAAACCAGTTG-3 ' 5 -TGAAAGTGAATACAAAACCTTGCAGCCTTCCAGG-3 ' 5 -CCACCTACAAAAAATGGCGTGGAACCAAAGCGACCCAGCCGAC-3 ' 5 -GACTGTCCACAACAGTACCAAACACGATTGTTG-3 ' 5 -GGAAGAAACTATTCCATGGCAGTATATCTTGTAAAACAGT-3 1 5 -CAGAGGTTACGAGCAAAGGGAATAAGGAATCCGGATCATTCTAGAG-3 1 5 -GGATCCAGACAGTGAAATAGCTACAACCAGCCTAAG-3 ' 5 -CTTGGTAAAATGCGGCTGACAATTCCGTGTCGGGCCCTTAC-3 ' 5 -CATCTACAATGTTTTGACGCAACTCTTTACATTCAGATG-3 ' 5 -GTCCTGTCTGTGATAAGAAGGCTCCATATGAACACC-3' 5 -TCCTAAAGTACTGTACAGACTGTGATGAAATACAATTTAAGGAGGATG-3' 5 -GGAAGTACAGGAAGTTTCTGCCTCTTACAATGGAGTC-3 ' 5 -CTTGAGCTCCACATTGGAGCATCAGGTAGCGTCTCACCAC-3 ' 5 -AGTGATTGACCTAACCATAGACAGTTCATCTGATGAAGAGGA-3 » 5 -CCAAGAGGACCTGTCCTTCCCTATCTCCCACATCACCACT-3 ' 5 -CTTCCACATCAAGCATCTCCAGTATCCCGCACCCCAAGCCTTC-3' 5 -TAATACCTCCCTCATCCAAGACTATAGGCATCCTTTCC-3 » 5 -CCATGCCTTACGACTTACAAGGATTAGATTTCTTTCCTTTCTTATCA-3' 5 -ACAACACCTCCTTGCTTGCCGCTGCAGCAGCAGCAGTTTCAGAT-3 » 5 -CTACACTCGTCTCGGTTTTTCCCGTATACCTCCTCACAG-3 ' 5 -GGAGGCAGTACTTCTCTGCCAACCACCAATGGAAGC-3 ' 5 -GGTTTCTTCCAACAGCCTAAGGGAAAGCCATAGCCACAC-3 ' 5 -CGGACACGGCATCCATCTTTGGCATCATACCAGACATTAT-3 • 5 -GCTGCTCCCATCCCCACCCCAGATCGAATGAACTTGGCAGA-3 ' 5 -GTGCTCTGTTTTACCTTACTCTGTTTAGAAAAGTATACAAGCGTG-3 • 5 -GAAATGTACAGAGAACAAAACTATATTTTCAGTT-3 ' 5 -CTTTTGTATATAAATCTAAGACTGCCTGTGTGATAAAACACTTG-3 ' Sequences of Table I or their complements are selected independently to form WBPl polynucleotides useful as hybridization probes. Typically, such sequences are placed in the same orientation and order as found in the naturally- occurring WBPl mRNA and/or gene, and may comprise one or more spacers of irrelevant sequence (e.g., pBR322, random-sequence, and the like) , such spacer sequences are typically selected independently and comprise between 0-300 nucleotides (0-100 amino acids, if fused in translational frame) . Also for example but not limitation, the following pair of PCR primers (amplimers) may be used to amplify murine or human WBPl sequences (e.g., by reverse transcriptase initiated PCR of RNA from WBPl expressing cells) : (forward) 5 '-CACGAGGCGGACAGTGCGGAACTAAAGCAAATGG-3 ' (reverse) 5 •-CAAGTGTTTTATCACACAGGCAGTCTTAGAT-3 ' If desired, PCR amplimers for amplifying substantially full- length cDNA copies may be selected at the discretion of the practitioner. Similarly, amplimers to amplify single WBPl exons or portions of the WBPl gene (murine or human) may be selected. Each of these sequences may be used as hybridization probes or PCR amplimers to detect the presence of WBPl mRNA, for example to diagnose a disease characterized by the presence of an elevated WBPl mRNA level in cells, or to perform tissue typing (i.e., identify tissues characterized by the expression of WBPl mRNA) , and the like. The sequences may also be used for detecting genomic WBPl gene sequences in a DNA sample, such as for forensic DNA analysis (e.g., by RFLP analysis, PCR product length(s) distribution, etc.) or for diagnosis of diseases characterized by amplification and/or rearrangements of the WBPl gene. For example but not limitation, suitable hybridization probes for detecting and/or quantifying the presence of p53UBC mRNA in a sample generally comprise at least one, preferably at least two, and more preferably all of the following human p53UBC sequences shown in Table II, or their complements: Table II: Selected Human p53UBC Polynucleotide Sequences 5 -GGACTTTGAACATGTCGGGGATCGCCCTCAGCAGACTCGCCCAG-3 ' 5 -AAGACCACCCATTTGGTTTCGTGGCTGTCCCAACA-3 ' 5 -CTCATGAACTGGGAGAGCGCCATTCCAGGAAAGAAAGGGAC-3' 5 -ACTACGGATGCTTTTCAAAGATGATTATCCATCTTC-3' 5 -CACCCGAATGTGTACTTCGGGACAGTGTGCCTGTCCATC-3 ' 5 -AGGACAAGGACTGGAGGCCAGCCATCACAATCAAACAGATC-3' 5 -TGAACCAAATATCCAAGACCCAGCTCAAGCAGAGGCCTACACG-3 • 5 -AACAGAGTGGAGTACGAGAAAAGGGTCCGAGCTCAAGCCA-3' 5 -AGCGACCTTGTGGCATCGTCAGAAGGAAGGGATTGGTTTGGC-3 • 5 -TTGCAAATCTAAAGTTGCTCCATACAATGACTAGTCACCT-3 • 5 -TCTTCCATTGCCGCCGCGGGTGTGCGGTCTCGATTCGCTG-3' 5 -CATACAGGGTCTCTTCTTCGGTCTTTTGTATTTTTGATTG-3 • 5 -ATATTGATGTCAGTATTTCAACTGCTGTAAAATTATAAAC-3 1 5 -GGGCGAGTTCCTCGCTCTGGGATGCAGGCATGCTTCTCAC-3' 5 -GGCCTCAGCTGGCTGTATGGAAATGCACCCTCCCTCCTGCGCTC-3 1 5 -CTTCTAGAACCTGGGCTGTGCTGCTTTTGAGCCTCAGACCCCAGG-3 ' 5 -TCTGCGCCACTTCCTTTGTGTTTATATGGCGTTTTGTCTGTG-3 ' 5 -CTGTGTTGCTGTTTAGAGTAAATAAACTGTTTATATA-3 1 5 -TCACCACCTCAGTTATACTCTTATTCCTAGATATTTGGGACA-3 ' 5 -CCTCCTCAAATACAGAATAAAAGCTGCTATGCCTGAGGCAT-3 • 5 -TTGTTGGTCCGGCACATCATATTTTACTATTTGTTTGAGGTATTTG-3 ' 5 -GTGAATAATCTTGTCTTTTTATTTTAATATACACAGCACAG-3' 5 -TAATTGCGTTTTGTGGACTTTACAACATGGCTAAACCCAT-3 » 5 -TAAATTGAAATGAATTAGGCCAGAGGAGATCAGACAT-3 ' 5 -GAATTTAAAGTTAGTCTTGAGAGAAACTTAGGTAAAAAG-3 ' 5 -TGTGAGAGTTGAAAGATATAAGTTCCAGAATGTTGTGGCA-3 • 5 -CTGGTTCCTAAAGACGGAGGAGACTCTCTCCCAGCACCTGACTTCCA-3' 5 -TGCCTGGGCTGTTCCTAGCCTGGAGCACTGTCCCCCGTCTCGAT-3 ' 5 -ACCCCTGCAGGGGCTGCCCTCTTTTGGCCTCCCACTGTGTCCCTTC-3 • 5 -CTGGCCTTGAATGTCTCTTTCTCACCAGTACCTTGCACAG-3 » Also for example but not limitation, the following pair of PCR primers (amplimers) may be used to amplify murine or human p53UBC sequences (e.g., by reverse transcriptase initiated PCR of RNA from p53UBC expressing cells) : (forward) 5 '-GAGGGACTTTGAACATGTCGGGGATCGCCCTCAG-3 ' (reverse) 5 '-GAGACATTCAAGGCCAGGCTGAGATCTAATGCACA-3 ' If desired, PCR amplimers for amplifying substantially full- length cDNA copies may be selected at the discretion of the practitioner. Similarly, amplimers to amplify single p53UBC exons or portions of the p53UBC gene (murine or human) may be selected. Each of these sequences may be used as hybridization probes or PCR amplimers to detect the presence of p53UBC mRNA, for example to diagnose a disease characterized by the presence of an elevated p53UBC mRNA level in cells, or to perform tissue typing (i.e., identify tissues characterized by the expression of p53UBC mRNA) , and the like. The sequences may also be used for detecting genomic p53UBC gene sequences in a DNA sample, such as for forensic DNA analysis (e.g., by RFLP analysis, PCR product length(s) distribution, etc.) or for diagnosis of diseases characterized by amplification and/or rearrangements of the p53UBC gene. Production of WBPl and p53UBC Polypeptides The nucleotide and amino acid sequences shown in Figs. 1A-1D and 2 enable those of skill in the art to produce polypeptides corresponding to all or part of the full-length human WBPl or p53UBC polypeptide sequence, respectively. Such polypeptides may be produced in prokaryotic or eukaryotic host cells by expression of polynucleotides encoding WBPl or p53UBC, or fragments and analogs thereof. Alternatively, such polypeptides may be synthesized by chemical methods or produced by in vitro translation systems using a polynucleotide template to direct translation. Methods for expression of heterologous proteins in recombinant hosts, chemical synthesis of polypeptides, and in vitro translation are well known in the art and are described further in Maniatis et al., Molecular Cloning: A Laboratory Manual (1989), 2nd Ed., Cold Spring Harbor, N.Y. and Berger and Kimmel, Methods in Enzymology, Volume 152, Guide to Molecular Cloning Technigues (1987) , Academic Press, Inc., San Diego, CA. Fragments or analogs of WBPl or p53UBC may be prepared by those of skill in the art. Preferred amino- and carboxy-termini of fragments or analogs of WBPl or p53UBC occur near boundaries of functional domains. For example, but not for limitation, such functional domains include: (1) domains conferring the property of binding to p53 , or (2) domains conferring the property of inducing a dominant p53 mutant phenotype when expressed at sufficient levels in cells expressing wild-type p53. Additionally, such functional domains might include: (1) domains conferring the property of binding to RNA poly erase species, (2) domains having the capacity to directly alter local chromatin structure, which may comprise catalytic activities (e.g., topoisomerases, endonucleases) and/or which may comprise structural features (e.g., zinc fingers, histone-binding moieties), and (3) domains which may interact with accessory proteins and/or transcription factors. One method by which structural and functional domains may be identified is by comparison of the nucleotide and/or amino acid sequence data shown in Figs. 1A-1D and 2 to public or proprietary sequence databases. Preferably, computerized comparison methods are used to identify sequence motifs or predicted protein conformation domains that occur in other proteins of known structure and/or function, such as the zinc fingers. For example, the NAD-binding domains of dehydrogenases, particularly lactate dehydrogenase and malate dehydrogenase, are similar in conformation and have amino acid sequences that are detectably homologous (Proteins, Structures and Molecular Principles, (1984) Creighton (ed.), W.H. Freeman and Company, New York, which is incorporated herein by reference) . Further, a method to identify protein sequences that fold into a known three-dimensional structure are known (Bowie et al. (1991) Science 253 : 164) . Thus, the foregoing examples demonstrate that those of skill in the art can recognize sequence motifs and structural conformations that may be used to define structural and functional domains in the WBPl and p53UBC sequences of the invention. Additionally, computerized comparison of sequences shown in Figs. 1A-1D and 2 to existing sequence databases can identify sequence motifs and structural conformations found in other proteins or coding sequences that indicate similar domains of the WBPl and p53UBC proteins. For example but not for limitation, the programs GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package (Genetics Computer Group, 575 Science Dr., Madison, WI) can be used to identify sequences in databases, such as GenBank/EMBL, that have regions of homology with a WBPl or p53UBC sequences. Such homologous regions are candidate structural or functional domains. Alternatively, other algorithms are provided for identifying such domains from sequence data. Further, neural network methods, whether implemented in hardware or software, may be used to: (1) identify related protein sequences and nucleotide sequences, and (2) define structural or functional domains in WBPl or p53UBC polypeptides (Brunak et al. (1991) J. Mol. Biol. 220: 49, which is incorporated herein by reference) . Fragments or analogs comprising substantially one or more functional domain may be fused to heterologous polypeptide sequences, wherein the resultant fusion protein exhibits the functional property(ies) conferred by the WBPl or p53UBC fragment. Alternatively, WBPl or p53UBC polypeptides wherein one or more functional domain have been deleted will exhibit a loss of the property normally conferred by the missing fragment. Although one class of preferred embodiments are fragments having amino- and/or carboxy-termini corresponding to amino acid positions near functional domains borders, alternative WBPl or p53UBC fragments may be prepared. The choice of the amino- and carboxy-termini of such fragments rests with the discretion of the practitioner and will be made based on experimental considerations such as ease of construction, stability to proteolysis, thermal stability, immunological reactivity, amino- or carboxyl-terminal residue modification, or other considerations. In addition to fragments, analogs of WBPl or p53UBC can be made. Such analogs may include one or more deletions or additions of amino acid sequence, either at the amino- or carboxy-termini, or internally, or both; analogs may further include sequence transpositions. Analogs may also comprise amino acid substitutions, preferably conservative substitutions. Additionally, analogs may include heterologous sequences generally linked at the amino- or carboxy-terminus, wherein the heterologous sequence(s) confer a functional property to the resultant analog which is not indigenous to the native WBPl or p53UBC protein. However, WBPl or p53UBC analogs must comprise a segment of 25 amino acids that has substantial similarity to a portion of the amino acid sequence shown in Figs. 1A-1D or 2, respectively, and which has at least one of the requisite functional properties enumerated (supra) . Preferred amino acid substitutions are those which: (1) reduce susceptibility to proteolysis, (2) reduce susceptibility to oxidation, (3) alter post-translational modification of the analog, possibly including phosphorylation, and (4) confer or modify other physicochemical or functional properties of such analogs, possibly including interaction with p53 or phosphorylation or dephosphorylation thereof. WBPl or p53UBC analogs include various muteins of a WBPl or p53UBC sequence other than the naturally-occurring peptide sequence. For example, single or multiple amino acid substitutions (preferably conservative amino acid substitutions) may be made in the naturally- occurring WBPl or p53UBC sequence (preferably in the portion of the polypeptide outside the functional domains) . Conservative amino acid substitution is a substitution of an amino acid by a replacement amino acid which has similar characteristics (e.g., those with acidic properties: Asp and Glu) . A conservative (or synonymous) amino acid substitution should not substantially change the structural characteristics of the parent sequence (e.g., a replacement amino acid should not tend to break a helix that occurs in the parent sequence, or disrupt other types of secondary structure that characterizes the parent sequence) . Examples of art-recognized polypeptide secondary and tertiary structures are described in Proteins, Structures and Molecular Principles r (1984) Creighton (ed.), W.H. Freeman and Company, New York; Introduction to Protein Structure, (1991) , C. Branden and J. Tooze, Garland Publishing, New York, NY; and Thornton et al. (1991) Nature 354 : 105; which are incorporated herein by reference) . Native WBPl or p53UBC proteins, fragments thereof, or analogs thereof can be used as reagents in p53 binding assays for identifying agents that interfere with p53 function, said agents are thereby identified as p53-modulatory agents, which are candidate drugs. Typically, in vitro p53 binding assays that measure binding of WBPl or p53UBC polypeptides to p53. WBPl or p53UBC polypeptides are typically contacted with p53 polypeptide(s) under aqueous conditions that permit specific binding in control binding reactions with a binding affinity of about 1 x 10 6 M -1 or greater (e.g., 10-250 mM NaCl or KC1 and 5-100 mM Tris HCI pH 5-9, usually pH 6-8), generally may including Zn +2 and/or Mn +2 and/or Mg +2 in the nanomolar to micromolar range (1 nM to 999 μM) . Specificity of binding is typically established by adding unlabeled competitor at various concentrations selected at the discretion of the practitioner. Examples of unlabeled protein competitors include, but are not limited to, the following: unlabeled WBPl or p53UBC polypeptide, bovine serum albumin, dry milk fractions, and nuclear protein extracts. Binding reactions wherein one or more agents are added are performed in parallel with a control binding reaction that does not include an agent. Agents which inhibit the specific binding of WBPl or p53UBC polypeptides to p53, as compared to a control reaction, are identified as candidate p53-modulatory drugs. WBPl and p53UBC polypeptides have many utilities, including but not limited to their use as oncotic pressure- enhancing solutes (typically WBPl and p53UBC polypeptides of 15-10,000 amino acids or more are dissolved in an aqueous solvent, such as PBS, to produce a solution having substantial oncotic pressure or as a non-specific blocking agent to replace albumin or milk whey proteins in immunoassay formats such as a Western blot preblock solution) , their use as nutritive foodstuffs, their use as a combustible energy source, and other uses described herein or apparent to the practitioner. Peptidomimetics of p53-Interacting Polypeptides In addition to p53-interacting polypeptides consisting only of naturally-occuring amino acids, WBPl or p53UBC peptidomimetics are also provided. Peptide analogs are commonly used in the pharmaceutical industry as non-peptide drugs with properties analogous to those of the template peptide. These types of non-peptide compound are termed "peptide mimetics" or "peptidomimetics" (Fauchere, J. (1986) Adv. Drug Res. 15: 29; Veber and Freidinger (1985) TINS p.392; and Evans et al. (1987) J. Med. Che 30: 1229, which are incorporated herein by reference) and are usually developed with the aid of computerized molecular modeling. Peptide mimetics that are structurally similar to therapeutically useful peptides may be used to produce an equivalent therapeutic or prophylactic effect. Generally, peptidomimetics are structurally similar to a paradigm polypeptide (i.e., a polypeptide that has a biological or pharmacological activity) , such as human WBPl or p53UBC , but have one or more peptide linkages optionally replaced by a linkage selected from the group consisting of: -CH 2 NH-, -CH 2 S-, -CH 2 -CH 2 -, -CH=CH- (cis and trans), -C0CH 2 -, -CH(0H)CH 2 -, and - CH 2 S0-, by methods known in the art and further described in the following references: Spatola, A.F. in "Chemistry and Biochemistry of Amino Acids, Peptides, and Proteins," B. Weinstein, eds., Marcel Dekker, New York, p. 267 (1983); Spatola, A.F., Vega Data (March 1983) , Vol. 1, Issue 3, "Peptide Backbone Modifications" (general review) ; Morley, J.S., Trends Pharm Sci (1980) pp. 463-468 (general review); Hudson, D. et al., Int J Pept Prot Res (1979) 14:177-185 (- CH 2 NH-, CH 2 CH 2 -) ; Spatola, A.F. et al., Life Sci (1986) 3.8:1243-1249 (-CH 2 -S) ; Hann, M.M. , J Chem Soc Perkin Trans I (1982) 307-314 (-CH-CH-, cis and trans) ; Almquist, R.G. et al., J Med Chem (1980) 11:1392-1398 (-C0CH 2 ~) ; Jennings-White, C. et al., Tetrahedron Lett (1982) 21:2533 (-C0CH 2 -) ; Szelke, M. et al., European Appln. EP 45665 (1982) CA: 92:39405 (1982) (-CH(OH)CH 2 -) ; Holladay, M.W. et al., Tetrahedron Lett (1983) 14:4401-4404 (-C(OH) CH 2 -) ; and Hruby, V.J. , Life Sci (1982) 11:189-199 (-CH 2 -S-) ; each of which is incorporated herein by reference. A particularly preferred non-peptide linkage is -CH 2 NH-. Such peptide mimetics may have significant advantages over polypeptide embodiments, including, for example: more economical production, greater chemical stability, enhanced pharmacological properties (half-life, absorption, potency, efficacy, etc.) , altered specificity (e.g., a broad-spectrum of biological activities) , reduced antigenicity, and others. Labeling of peptidomimetics usually involves covalent attachment of one or more labels, directly or through a spacer (e.g., an amide group) , to non-interfering position(s) on the peptidomimetic that are predicted by quantitative structure-activity data and/or molecular modeling. Such non-interfering positions generally are positions that do not form direct contacts with the macromolecules(s) (e.g., p53 ) to which the peptidomimetic binds to produce the therapeutic effect. Derivitization (e.g., labelling) of peptidomimetics should not substantially interfere with the desired biological or pharmacological activity of the peptidomimetic. Peptidomimetics of WBPl or p53UBC may be used as competitive or noncompetitive agonists or antagonists of WBPl or p53UBC function, respectively. For example, a WBPl peptidomimetic administered to a cell containing WBPl protein and may compete with the naturally- occurring WBPl protein and reduce WBPl activity. Alternatively, an WBPl peptidomimetic administered to a cell lacking WBPl may provide WBPl function (e.g., modulation of p53 activity) or the like. Systematic substitution of one or more amino acids of a consensus sequence with a D-amino acid of the same type (e.g., D-lysine in place of L-lysine) may be used to generate more stable peptides. In addition, constrained peptides (including cyclized peptides) comprising a consensus sequence or a substantially identical consensus sequence variation may be generated by methods known in the art (Rizo and Gierasch (1992) Ann. Rev. Biochem. 61: 387, incorporated herein by reference) ; for example, by adding internal cysteine residues capable of forming intramolecular disulfide bridges which cyclize the peptide. The amino acid sequences of WBPl or p53UBC polypeptides identified herein will enable those of skill in the art to produce polypeptides corresponding to WBPl or p53UBC peptide sequences and sequence variants thereof. Such polypeptides may be produced in prokaryotic or eukaryotic host cells by expression of polynucleotides encoding a WBPl or p53UBC peptide sequence, frequently as part of a larger polypeptide. Alternatively, such peptides may be synthesized by chemical methods. Methods for expression of heterologous proteins in recombinant hosts, chemical synthesis of polypeptides, and in vitro translation are well known in the art and are described further in Maniatis et al., Molecular Cloning: A Laboratory Manual (1989) , 2nd Ed., Cold Spring Harbor, N.Y.; Berger and Kimmel, Methods in Enzvmology, Volume 152 , Guide to Molecular Cloning Techniques (1987) , Academic Press, Inc., San Diego, CA; Merrifield, J. (1969) J. Am. Chem. Soc. 91: 501; Chaiken I.M. (1981) CRC Crit. Rev. Biochem. 11: 255; Kaiser et al. (1989) Science 243: 187; Merrifield, B. (1986) Science 232: 342; Kent, S.B.H. (1988) Ann. Rev. Biochem. 57: 957; and Offord, R.E. (1980) Semisvnthetic Proteins, Wiley Publishing, which are incorporated herein by reference) . Production and Applications of -WBPl or -p53UBC Antibodies Native p53-interacting polypeptides, fragments thereof, or analogs thereof, may be used to immunize an animal for the production of specific antibodies. These antibodies may comprise a polyclonal antiseru or may comprise a monoclonal antibody produced by hybridoma cells. For general methods to prepare antibodies, see Antibodies: A Laboratory Manual,, (1988) E. Harlow and D. Lane, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, which is incorporated herein by reference. For example but not for limitation, a recombinantly produced fragment of human WBPl or p53UBC can be injected into a rat along with an adjuvant following immunization protocols known to those of skill in the art so as to generate an immune response. Typically, approximately at least 1-50 μg of a WBPl or p53UBC fragment or analog is used for the initial immunization, depending upon the length of the polypeptide. Alternatively or in combination with a recombinantly produced WBPl or p53UBC polypeptide, a chemically synthesized peptide having a WBPl or p53UBC sequence (e.g., peptides exemplified in Tables III and IV, infra) may be used as an immunogen to raise antibodies which bind a WBPl or p53UBC protein, respectively, such as a native human WBPl or p53UBC polypeptide having the sequence shown essentially in Figs. 1A- 1D or Fig. 2. Immunoglobulins which bind the recombinant fragment with a binding affinity of at least 1 x 10 7 M -1 can be harvested from the immunized animal as an antiserum, and may be further purified by immunoaffinity chromatography or other means. Additionally, spleen cells are harvested from the immunized animal (typically rat or mouse) and fused to myeloma cells to produce a bank of antibody-secreting hybridoma cells. The bank of hybrido as can be screened for clones that secrete immunoglobulins which bind the recombinantly produced WBPl or p53UBC polypeptide (or chemically synthesized WBPl or p53UBC polypeptide) with an affinity of at least 1 x 10 6 M -1 . Animals other than mice and rats may be used to raise antibodies; for example, goats, rabbits, sheep, and chickens may also be employed to raise antibodies reactive with a WBPl or p53UBC protein. Transgenic mice having the capacity to produce substantially human antibodies also may be immunized and used for a source of -WBPl or -p53UBC antiserum and/or for making monoclonal-secreting hybridomas. Bacteriophage antibody display libraries may also be screened for binding to a WBPl or p53UBC polypeptide, such as a full-length human protein, a fragment (e.g., a peptide having a sequence shown in Table III or IV, infra) , or a fusion protein comprising a WBPl or p53UBC polypeptide sequence of at least 14 contiguous amino acids as shown in Figs. 1A-1D or Fig. 2 or a polypeptide sequence of Table III or IV (infra) . Combinatorial libraries of antibodies have been generated in bacteriophage lambda expression systems which may be screened as bacteriophage plaques or as colonies of lysogens (Huse et al. (1989) Science 246: 1275; Caton and Koprowski (1990) Proc. Natl. Acad. Sci. (U.S.A.) 87: 6450; Mullinax et al (1990) Proc. Natl. Acad. Sci. (U.S.A.) 87: 8095; Persson et al. (1991) Proc. Natl. Acad. Sci. (U.S.A.) 88: 2432) . Various embodiments of bacteriophage antibody display libraries and lambda phage expression libraries have been described (Kang et al. (1991) Proc. Natl. Acad. Sci. (U.S.A. ) 88: 4363; Clackson et al. (1991) Nature 352: 624; McCafferty et al. (1990) Nature 348: 552; Burton et al. (1991) Proc. Natl. Acad. Sci. (U.S.A.) 88: 10134; Hoogenboom et al. (1991) Nucleic Acids Res. 19: 4133; Chang et al. (1991) J. Immunol. 147: 3610; Breitling et al. (1991) Gene 104: 147; Marks et al. (1991) J. Mol. Biol. 222: 581; Barbas et al. (1992) Proc. Natl. Acad. Sci. (U.S.A.) 89: 4457; Hawkins and Winter (1992) J. Immunol. 22: 867; Marks et al. (1992) Biotechnology 10: 779; Marks et al. (1992) J. Biol. Chem. 267: 16007; Lowman et al (1991) Biochemistry 30: 10832; Lerner et al. (1992) Science 258: 1313, incorporated herein by reference) . Typically, a bacteriophage antibody display library is screened with a WBPl or p53UBC polypeptide that is immobilized (e.g., by covalent linkage to a chromatography resin to enrich for reactive phage by affinity chromatography) and/or labeled (e.g., to screen plaque or colony lifts). WBPl or p53UBC polypeptides which are useful as im unogens, for diagnostic detection of -WBPl or -p53UBC antibodies in a sample, for diagnostic detection and quantitation of WBPl or p53UBC protein in a sample (e.g., by standardized competitive ELISA) , or for screening a bacteriophage antibody display library, are suitably obtained in substantially pure form, that is, typically about 50 percent (w/w) or more purity, substantially free of interfering proteins and contaminants. Preferably, these polypeptides are isolated or synthesized in a purity of at least 80 percent (w/w) and, more preferably, in at least about 95 percent (w/w) purity, being substantially free of other proteins of humans, mice, or other contaminants. Preferred immunogens comprise at least one WBPl or p53UBC polypeptide sequence shown in Table III or IV, either as a discrete peptide or as part of a fusion polypeptide (e.g., with a β- galactosidase or glutathione S-transferase sequence) . WBPl or p53UBC immunogens comprise at least one, typically several of such immunogenic epitopes. For some applications of these antibodies, such as identifying immunocrossreactive proteins, the desired antiserum or monoclonal antibody(ies) is/are not monospecific. In these instances, it may be preferable to use a synthetic or recombinant fragment of WBPl or p53UBC as an antigen rather than using the entire native protein. More specifically, where the object is to identify immunocrossreactive polypeptides that comprise a particular structural moiety, such as a p53-binding domain, it is preferable to use as an antigen a fragment corresponding to part or all of a commensurate structural domain in the p53-interacting polypeptide. Production of recombinant or synthetic fragments having such defined amino- and carboxy-termini is provided by the WBPl and p53UBC sequences shown in Figs. 1A-1D and Fig. 2, respectively. If an antiserum is raised to a WBPl or p53UBC fusion polypeptide, such as a fusion protein comprising a WBPl or p53UBC immunogenic epitope fused to -galactosidase or glutathione S-transferase, the antiserum is preferably preadsorbed with the non-p53-interacting polypeptide fusion partner (e.g, β-galactosidase or glutathione S-transferase) to deplete the antiserum of antibodies that react (i.e., specifically bind to) the non-p53-interacting polypeptide portion of the fusion protein that serves as the immunogen. Monoclonal or polyclonal antibodies which bind to the human and/or murine WBPl or p53UBC protein can be used to detect the presence of human or murine WBPl or p53UBC polypeptides in a sample, such as a Western blot of denatured protein (e.g., a nitrocellulose blot of an SDS-PAGE) obtained from a cell sample of a patient. Preferably quantitative detection is performed, such as by densitometric scanning and signal integration of a Western blot. The monoclonal or polyclonal antibodies will bind to the denatured WBPl or p53UBC epitopes and may be identified visually or by other optical means with a labeled second antibody or labeled Staphylococcus aureus protein A by methods known in the art. Frequently, denatured WBPl or p53UBC will be used as the target antigen so that more epitopes may be available for binding. Table III: WBPl Polypeptide Sequences and Epitopes -HYNTSLLAAAAAAVSDDQDL- -LHSSRFFPYTSSQMFLDQLSA- -LPPTKNGVEPKRPSRPINI- -SLVRLSTTVPNTIWSWTA- -KELYRRRFPQKIMTPADLSIPN- -KLQKLPFYDLLDELIK- -EKLTADPDSEIATTSLRVS- -LLCPLGKMRLTIPCRALTCS- -IGRNYSMAVYLVKQLSSTV- -LLQRLRAKGIRNPDHSRALI- -DFTVQVQLRFCLSETSCPQE- -HFPPNLCVKVNTKPCSLPG- -TSLASDNSQRFRETCFAF- -PQQVQQISSSMDISGTKC- -LQCFDATLYIQMNEKKPTW- -VCPVCDKKAPYEHLIIDGL- -EILKYCTDCDEIQFKEDGT- -WAPMRSKKEVQEVSASYNGV- -DGCLSSTLEHQVASHHQSSN- -KNKKVEVIDLTIDSSSDEEEEE- -EEPSAKRTCPSLSPTSPLNN- -KGILSLPHQASPVSRTPSLP- -AVDTSYINTSLIQDYRHPFH- -TPMPYDLQGLDFFPFLSGD- -SLVSSNSLRESHSHTVTNR- -SSTDTASIFGIIPDIISLD- -HSSPMPATLSPSTIPQLTYDG- -HPASSPLLPVSLLGPKHELELPH- -ELPHLTSALHPVHPDIKLQ- -FAFALTPQQVQQISSSMDISGTKC- Such WBPl sequences as shown in Table III may be used as an immunogenic peptide directly (e.g., to screen bacteriophage antibody display libraries or to immunize a rabbit) , or may be conjugated to a carrier macromolecule (e.g., BSA) or may compose part of a fusion protein to be used as an immunogen. A preferred WBPl polypeptide comprises the following amino acids sequences: -PASSPLLPVSLLGPKHELEH- -PQQVQQISSSMDISGTKC-; -LLQRLRAKGIRNPDHSRALI- -WAPMRSKKEVQEVSASYNGV-; -EEPSAKRTCPSLSPTSPLNN- -TPMPYDLQGLDFFPFLSGD-; -SLVSSNSLRESHSHTVTNR-; -SSTDTASIFGIIPDIISLD-; and may comprise other intervening and/or terminal sequences; generally such polypeptides are less than 1000 amino acids in length, more usually less than about 500 amino acids in length; often spacer peptide sequences or terminal peptide sequences, if present, correspond to naturally occurring polypeptide sequences, generally mammalian polypeptide sequences. Preferably, the order of the amino acid sequences, from amino-terminal to carboxy-terminal direction are: (1) -PASSPLLPVSLLGPKHELEH- (2) -PQQVQQISSSMDISGTKC-; (3) -LLQRLRAKGIRNPDHSRALI- (4) -WAPMRSKKEVQEVSASYNGV-; (5) -EEPSAKRTCPSLSPTSPLNN- (6) -TPMPYDLQGLDFFPFLSGD-; (7) -SLVSSNSLRESHSHTVTNR-; (8) -SSTDTASIFGIIPDIISLD-. One application of the preferred WBPl polypeptide just recited is as a commercial immunogen to raise a-WBPl antibodies in a suitable animal and/or as a commercial immunodiagnostic reagent for quantitative ELISA (e.g., competitive ELISA) or competitive RIA in conjunction with the anti-PtøPl antibodies provided by the invention, such as for calibration of standardization of such immunoassays for staging or diagnosis of P Pl-expressing tumors in humans or cell typing or identification of cells. Such immunological detection may be used to detect denatured WBPl polypeptides (e.g., Western blots of SDS-polyacrylamide gels) wherein a variety of epitopes are exposed in the denatured WBPl protein or peptide fragments (e.g., following proteolytic digestion) . The preferred WBPl polypeptide just recited will find many other uses in addition to serving as an immunogen or immunological reagent. One or more of the above-listed sequences may be incorporated into a fusion protein with a fusion partner such as human serum albumin, GST, etc. For such fusion proteins in excess of 1000 amino acids, deletions in the fusion partner (albumin) moiety may be made to bring the size to about 1000 amino acids or less, if desired. In some embodiments, it will be desirable to employ a polyvalent WBPl antigen, comprising at least two WBPl immunogenic epitopes in covalent linkage, usually in peptide linkage. Such polyvalent WBPl antigens typically comprise multiple WBPl antigenic peptides from the same species (e.g., human or mouse) , but may comprise a mix of antigenic peptides from WBPl proteins of different species (i.e., an interspecies WBPl polyvalent antigen) . Frequently, the spatial order of the antigenic peptide sequences in the primary amino acid sequence of a polyvalent antigen occurs in the same orientation as in the naturally occurring WBPl protein (i.e., a first antigenic peptide sequence that is amino-terminal to a second antigenic peptide sequence in a naturally occurring WBPl protein will be amino-terminal to said second antigenic peptide sequence in a polyvalent antigen. Frequently, spacer peptide sequences will be used to link antigenic peptide sequences in a polyvalent antigen, such spacer peptide sequences may be predetermined, random, or pseudorandom sequences. Spacer peptide sequences may correspond to sequences known to be non-immunogenic to the animal which is to be immunized with the polyvalent antigen, such as a sequence to which the animal has been tolerized. Although many examples of such polyvalent antigens may be given, the following embodiment is provided for illustration and not limitation: -PQQVQQISSSMDISGTKC-(aal) -EEPSAKRTCPSLSPTSPLNN-(aa2)- SLVSSNSLRESHSHTVTNR- where (aal) and (aa2) are peptide spacers of at least one amino acid and less than 1000 amino acids; aal is a peptide sequence selected independently from the aa2 peptide sequence; the length of aal (which may be composed of multiple different amino acids) is independent of the length of aa2 (which may be composed of multiple different amino acids) . A preferred type of WBPl polypeptide immunogen comprises the 597 amino acid long polypeptide sequence: 1 MKIKELYRRR FPQKIMTPAD LSIPNVHSSP MPATLSPSTI PQLTYDGHPA 51 SSPLLPVSLL GPKHELELPH LTSALHPVHP DIKLQKLPFY DLLDELIKPT 101 SLASDNSQRF RETCFAFALT PQQVQQISSS MDISGTKCDF TVQVQLRFCL 151 SETSCPQEDH FPPNLCVKVN TKPCSLPGYL PPTKNGVEPK RPSRPINITS 201 LVRLSTTVPN TIWSWTAEI GRNYSMAVYL VKQLSSTVLL QRLRAKGIRN 251 PDHSRALIKE KLTADPDSEI ATTSLRVSLL CPLGKMRLTI PCRALTCSHL 301 QCFDATLYIQ MNEKKPTWVC PVCDKKAPYE HLIIDGLFME ILKYCTDCDE 351 IQFKEDGTWA PMRSKKEVQE VSASYNGVDG CLSSTLEHQV ASHHQSSNKN 401 KKVEVIDLTI DSSSDEEEEE PSAKRTCPSL SPTSPLNNKG ILSLPHQASP 451 VSRTPSLPAV DTSYINTSLI QDYRHPFHMT PMPYDLQGLD FFPFLSGDNQ 501 HYNTSLLAAA AAAVSDDQDL LHSSRFFPYT SSQMFLDQLS AGGSTSLPTT 551 NGSSSGSNSS LVSSNSLRES HSHTVTNRSS TDTASIFGII PDIISLD 597 A preferred species consists of the 597 amino acid sequence shown above, without amino-terminal or carboxy-terminal extensions. In one variation a WBPl polypeptide comprises a p53- binding segment comprising the sequence: -SSTLEHQVASHHQSSNKNKKVEVIDLTIDSSSDEEEEEPSAKRTCPSLSPTSPLNNKG ILSLPHQASPVSRTPSLPAVDTSYINTSLIQDYRHPFHMTPMP-. For example and not limitation, such a polypeptide can consist of the sequence: SSTLEHQVASIIHQSSNKNKKVEVIDLTIDSSSDEEEEEPSAKRTCP SLSPTSPLNNKGILSLPHQASPVSRTPSLPAVDTSYINTSLIQDYRHPFHMTPMP. Polynucleotides encoding epitopes having substantial identity to these preferred epitopes are often employed. Such polynucleotides have a variety of uses, including as WBPl probes, as templates for producing polypeptides comprising a WBPl epitope whereby such proteins are WBPl immunogens or commercial diagnostic reagents for standardizing a WBPl immunoassay, as polynucleotide vaccines (immunogens) when fused to a secretory sequence for administering to an animal and making -WBPl antisera and hybridomas; such polynucleotides can also be used as foodstuffs, combustible energy sources, and viscosity-enhancing solutes. Table IV: p53UBC Polypeptide Seguences and Epitopes -GTLNMSGIALSRLAQERKA-; -DHPFGFVAVPTKNPDGTMNLMNW-; -TPWEGGLFKLRMLFKDDYPSSPPK-; -VYFGTVCLSILEEDKDWRPA-; -QELLNEPNIQDPAQAEAYTIYCQNR-; -AQAKNLRPHKQRPCGIV-; -RVCGLDSLNCPFPYRVSSSVFCIFD-; -LFKLRMLFKDDYPSSPPKCKFEPP- Such p53UBC sequences as shown in Table IV may be used as an immunogenic peptide directly (e.g., to screen bacteriophage antibody display libraries or to immunize a rabbit) , or may be conjugated to a carrier macromolecule (e.g. , BSA) or may compose part of a fusion protein to be used as an immunogen. A preferred p53UBC polypeptide comprises the following amino acids sequences: -RKAWRKDHPFGFVAVPTKNP-; -NIQDPAQAEAYTIYCQNRVEYE-; -GLVWQELVYNIFANLKLLHT-; -GLDSLNCPFPYRVSSSVFCI-; -KLAFILILMSVFQL-; and may comprise other intervening and/or terminal sequences; generally such polypeptides are less than 1000 amino acids in length, more usually less than about 500 amino acids in length; often spacer peptide sequences or terminal peptide sequences, if present, correspond to naturally occurring polypeptide sequences, generally mammalian polypeptide sequences. Preferably, the order of the amino acid sequences, from amino-terminal to carboxy-terminal direction are: (1) -RKAWRKDHPFGFVAVPTKNP-; (2) -NIQDPAQAEAYTIYCQNRVEYE-; (3) -GLVWQELVYNIFANLKLLHT-; (4) -GLDSLNCPFPYRVSSSVFCI-; (5) -KLAFILILMSVFQL-. One application of the preferred p53UBC polypeptide just recited is as a commercial immunogen to raise a-p53UBC antibodies in a suitable animal and/or as a commercial immunodiagnostic reagent for quantitative ELISA (e.g., competitive ELISA) or competitive RIA in conjunction with the anti-p53C7JSC antibodies provided by the invention, such as for calibration of standardization of such immunoassays for staging or diagnosis of p53UBC-expressing tumors in humans or cell typing or identification of cells. Such immunological detection may be used to detect denatured p53UBC polypeptides (e.g., Western blots of SDS-polyacrylamide gels) wherein a variety of epitopes are exposed in the denatured p53UBC protein or peptide fragments (e.g., following proteolytic digestion) . The preferred p53UBC polypeptide just recited will find many other uses in addition to serving as an immunogen or immunological reagent. One or more of the above- listed sequences may be incorporated into a fusion protein with a fusion partner such as human serum albumin, GST, etc. For such fusion proteins in excess of 1000 amino acids, deletions in the fusion partner (albumin) moiety may be made to bring the size to about 1000 amino acids or less, if desired. In some embodiments, it will be desirable to employ a polyvalent p53UBC antigen, comprising at least two p53UBC immunogenic epitopes in covalent linkage, usually in peptide linkage. Such polyvalent p53ϋBC antigens typically comprise multiple p53UBC antigenic peptides from the same species (e.g., human or mouse), but may comprise a mix of antigenic peptides from p53UBC proteins of different species (i.e., an interspecies p53UBC polyvalent antigen) . Frequently, the spatial order of the antigenic peptide sequences in the primary amino acid sequence of a polyvalent antigen occurs in the same orientation as in the naturally occurring p53UBC protein (i.e., a first antigenic peptide sequence that is amino-terminal to a second antigenic peptide sequence in a naturally occurring p53UBC protein will be amino-terminal to said second antigenic peptide sequence in a polyvalent antigen. Frequently, spacer peptide sequences will be used to link antigenic peptide sequences in a polyvalent antigen, such spacer peptide sequences may be predetermined, random, or pseudorandom sequences. Spacer peptide sequences may correspond to sequences known to be non-immunogenic to the animal which is to be immunized with the polyvalent antigen, such as a sequence to which the animal has been tolerized. Although many examples of such polyvalent antigens may be given, tne following embodiment is provided for illustration and not limitation: -TLNMSGIALSRLAQER-(aal) -GIQELLNEPNIQDPAQAEAYTI-(aa2) - AGMLLTVQSCTWPQLAVWKCT- where (aal) and (aa2) are peptide spacers of at least one amino acid and less than 1000 amino acids; aal is a peptide sequence selected independently from the aa2 peptide sequence; the length of aal (which may be composed of multiple different amino acids) is independent of the length of aa2 (which may be composed of multiple different amino acids) . A preferred species of p53UBC polypeptide immunogen is the 253 amino acid long human p53UBC protein shown below: 1 RGTLNMSGIA LSRLAQERKA RKDHPFGFV AVPTKNPDGT MNLMNWESAI 51 PGKKGTPWEG GLFKLRMLFK DDYPSSPPKC KFEPPLFHPN VYFGTVCLSI 101 LEEDKDWRPA ITIKQIL GI QELLNEPNIQ DPAQAEAYTI YCQNRVEYEK 151 RVRAQAKNLR PHKQRPCGIV RRKGLVWQEL VYNIFANLKL LHTMTSHLGG 201 LGGRHLPLPP RVCGLDSLNC PFPYRVSSSV FCIFDCYVKL AFILILMSVF 251 QLL Immunogenic WBPl or p53UBC peptides may be used to immunize an animal to raise anti-PtøPI and anti-p53£7BC antibodies and/or as a source of spleen cells for making a hybridoma library from which to select hybridoma clones which secrete a monoclonal antibody which binds to a WBPl or p53UBC protein with an affinity of 1 x 10 7 M "*1 or greater, preferably at least 1 x 10 8 M -1 to 1 x 10 9 M -1 . Such immunogenic WBPl or p53UBC peptides can also be used to screen bacteriophage antibody display libraries directly. One use of such antibodies is to screen cDNA expression libraries, preferably containing cDNA derived from human or murine mRNA from various tissues, for identifying clones containing cDNA inserts which encode structurally- related, immunocrossreactive proteins, that are candidate novel p53-interacting polypeptides. Such screening of cDNA expression libraries is well known in the art, and is further described in Young et al. (1983) Proc. Natl. Acad. Sci. (U.S.A. ) 80: 1194 as well as other published sources. Another use of such antibodies is to identify and/or purify immunocrossreactive proteins that are structurally or evolutionarily related to the native WBPl or p53UBC protein or to the corresponding WBPl or p53UBC fragment (e.g., functional domain; p53-binding domain) used to generate the antibody. It is believed that such antibodies will find commercial use as such reagents for research applications, just as other antibodies (and biological reagents - such as restriction enzymes and polymerases) are sold commercially. Various other uses of such antibodies are to diagnose and/or stage neoplasms or other cell proliferation disease states, and for therapeutic application (e.g., as cationized antibodies or by targeted liposomal delivery) to treat neoplasia, inflammation, wound healing, graft rejection, and the like. The antibodies can also be used to quantitate WBPl and/or p53UBC protein in a sample (e.g., via ELISA or Western blot) to provide a standard value(s) for comparison to other polypeptides detected in the same sample (e.g., to verify that lanes of a polyacrylamide gel transferred to a membrane in a Western blot each comprise comparable levels of WBPl and/or p53UBC and specifically differ in levels of a test polypeptide) . Polynucleotides encoding epitopes having substantial identity to these preferred epitopes are often employed. Such polynucleotides have a variety of uses, including as p53UBC probes, as templates for producing polypeptides comprising a p53UBC epitope whereby such proteins are p53UBC immunogens or commercial diagnostic reagents for standardizing a p53UBC immunoassay, as polynucleotide vaccines (immunogens) when fused to a secretory sequence for administering to an animal and making -p53UBC antisera and hybridomas; such polynucleotides can also be used as foodstuffs, combustible energy sources, and viscosity- enhancing solutes. WBPl Polynucleotides Disclosure of the coding sequence for human WBPl shown in Figs. 1A-1D and the sequence of the 597 amino acid long WBPl polypeptide (supra) makes possible the construction of isolated polynucleotides that can direct the expression of WBPl , fragments thereof, or analogs thereof. Such polypeptides can comprise any degenerate nucleotide sequence encoding a WBPl polypeptide sequence of Figs. 1A-1D. Further, the sequences in Figs. 1A-1D make possible the construction of nucleic acid hybridization probes and PCR primers that can be used to detect RNA and DNA sequences encoding WBPl . Polynucleotides encoding full-length WBPl or fragments or analogs thereof, may include sequences that facilitate transcription (expression sequences) and translation of the coding sequences, such that the encoded polypeptide product is produced. Construction of such polynucleotides is well known in the art and is described further in Maniatis et al., Molecular Cloning: A Laboratory Manual, 2nd Ed. (1989) , Cold Spring Harbor, N.Y. For example, but not for limitation, such polynucleotides can include a promoter, a transcription termination site (polyadenylation site in eukaryotic expression hosts) , a ribosome binding site, and, optionally, an enhancer for use in eukaryotic expression hosts, and, optionally, sequences necessary for replication of a vector. A typical eukaryotic expression cassette will include a polynucleotide sequence encoding a IVBP1 polypeptide linked downstream (i.e., in translational reading frame orientation; polynucleotide linkage) of a promoter such as the HSV tk promoter or the pgk (phosphoglycerate kinase) promoter, optionally linked to an enhancer and a downstream polyadenylation site (e.g., an SV40 large T Ag poly A addition site) . A preferred WBPl polynucleotide encodes a WBPl polypeptide that comprises at least one of the amino acids sequences shown in Table III. The degeneracy of the genetic code gives a finite set of polynucleotide sequences encoding these amino acid sequences; this set of degenerate sequences may be readily generated by hand or by computer using commercially available software (Wisconsin Genetics Software Package Release 7.0) . Thus, isolated polynucleotides typically less than approximately 10,000 nucleotides in length and comprising sequences encoding each of the following amino acid sequences: -ELPHLTSALHPVHPD-; -PQQVQQISSSMDISGTKC-; -LLQRLRAKGIRNPDHSRALI-; -WAPMRSKKEVQEVSASYNGV-; -EEPSAKRTCPSLSPTSPLNN-; -TPMPYDLQGLDFFPFLSGD-; -SLVSSNSLRESHSHTVTNR-; -SSTDTASIFGIIPDIISLD-; are provided and may be used for, among other uses, the expression of a WBPl polypeptide which can be used as an immunogen, immunological reagent, and the like. Such polynucleotides typically comprise an operably linked promoter for driving expression in a suitable prokaryotic or eukaryotic host cell. One exemplification of such a polynucleotide is the human WBPl cDNA sequence of Figs. 1A-1D cloned in operable linkage to the mammalian expression vector pSRo:, many alternative embodiments will be apparent to those of skill in the art, including the use of alternative expression vectors (e.g., pBC12BI and p91023 (B) ; Hanahan J (1983) J. Mol. Biol. 166: 577; Cullen et al. (1985) J. Virol. 51: 515; Lomedico PT (1982) Proc. Natl. Acad. Sci. (U.S.A.) 79: 5798; Morinaga et al. (1984) Bio/Technology 2_- 636) . Additionally, where expression of a polypeptide is not desired, polynucleotides of this invention need not encode a functional protein. Polynucleotides of this invention may serve as hybridization probes and/or PCR primers (amplimers) and/or LCR oligomers for detecting WBPl RNA or DNA sequences. Alternatively, polynucleotides of this invention may serve as hybridization probes or primers for detecting RNA or DNA sequences of related genes, such genes may encode structurally or evolutionarily related proteins. For such hybridization and PCR applications, the polynucleotides of the invention need not encode a functional polypeptide. Thus, polynucleotides of the invention may contain substantial deletions, additions, nucleotide substitutions and/or transpositions, so long as specific hybridization or specific amplification to the WBPl sequence is retained. Specific hybridization is defined hereinbefore, and can be roughly summarized as the formation of hybrids between a polynucleotide of the invention (which may include substitutions, deletions, and/or additions) and a specific target polynucleotide such as human WBPl mRNA so that a single band is identified corresponding to each WBPl isoform on a Northern blot of RNA prepared from 1VBP1-expressing cells (i.e., hybridization and washing conditions can be established that permit detection of discrete WBPl mRNA band(s)) . Thus, those of ordinary skill in the art can prepare polynucleotides of the invention, which may include substantial additions, deletions, substitutions, or transpositions of nucleotide sequence as compared to sequences shown in Figs. 1A-1D and determine whether specific hybridization is a property of the polynucleotide by performing a Northern blot using RNA prepared from a cell line which expresses 1VBP1 mRNA and/or by hybridization to a WBPl DNA clone (cDNA or genomic clone) . Specific amplification is defined as the ability of a set of PCR amplimers, when used together in a PCR reaction with a WBPl polynucleotide, to produce substantially a single major amplification product which corresponds to a IVBP1 gene sequence or mRNA sequence. Generally, human genomic DNA or mRNA from WBPl expressing human cells is used as the template DNA sample for the PCR reaction. PCR amplimers that exhibit specific amplification are suitable for quantitative determination of WBPl mRNA by quantitative PCR amplification. WBPl allele-specific amplification products, although having sequence and/or length polymorphisms, are considered to constitute a single amplification product for purposes of this definition. Generally, hybridization probes comprise approximately at least 25 consecutive nucleotides of a sequence shown in Figs. 1A-1D (for human WBPl detection, respectively) , preferably the hybridization probes contain at least 50 consecutive nucleotides of a sequence shown in Figs. 1A-1D, and more preferably comprise at least 100 consecutive nucleotides of a sequence shown in Figs. 1A-1D. PCR amplimers typically comprise approximately 25 to 50 consecutive nucleotides of a sequence shown in Figs. 1A-1D, and usually consist essentially of approximately 25 to 50 consecutive nucleotides of a sequence shown in Figs. 1A-1D with additional nucleotides, if present, generally being at the 5' end so as not to interfere with polymerase-mediated chain extension. PCR amplimer design and hybridization probe selection are well within the scope of discretion of practioners of ordinary skill in the art. p53UBC Polynucleotides Disclosure of the coding sequence for human p53UBC shown in Fig. 2 and the sequence of the 253 amino acid long p53UBC polypeptide (supra) makes possible the construction of isolated polynucleotides that can direct the expression of p53UBC, fragments thereof, or analogs thereof. Further, the sequences in Figs. 1A-1D make possible the construction of nucleic acid hybridization probes and PCR primers that can be used to detect RNA and DNA sequences encoding p53UBC. Polynucleotides encoding full-length p53UBC or fragments or analogs thereof, may include sequences that facilitate transcription (expression sequences) and translation of the coding sequences, such that the encoded polypeptide product is produced. Construction of such polynucleotides is well known in the art and is described further in Maniatis et al., Molecular Cloning: A Laboratory Manual, 2nd Ed. (1989) , Cold Spring Harbor, N.Y. For example, but not for limitation, such polynucleotides can include a promoter, a transcription termination site (polyadenylation site in eukaryotic expression hosts) , a ribosome binding site, and, optionally, an enhancer for use in eukaryotic expression hosts, and, optionally, sequences necessary for replication of a vector. A typical eukaryotic expression cassette will include a polynucleotide sequence encoding a p53UBC polypeptide linked downstream (i.e., in translational reading frame orientation; polynucleotide linkage) of a promoter such as the HSV tk promoter or the pgk (phosphoglycerate kinase) promoter, optionally linked to an enhancer and a downstream polyadenylation site (e.g., an SV40 large T Ag poly A addition site) . A preferred p53UBC polynucleotide encodes a p53UBC polypeptide that comprises at least one of the amino acids sequences shown in Table IV. The degeneracy of the genetic code gives a finite set of polynucleotide sequences encoding these amino acid sequences; this set of degenerate sequences may be readily generated by hand or by computer using commercially available software (Wisconsin Genetics Software Package Release 7.0) . Thus, isolated polynucleotides typically less than approximately 10,000 nucleotides in length and comprising sequences encoding each of the following amino acid sequences: -RKAWRKDHPFGFVAVPTKNP-; -NIQDPAQAEAYTIYCQNRVEYE-; -GLVWQELVYNIFANLKLLHT-; -GLDSLNCPFPYRVSSSVFCI-; -KLAFILILMSVFQL-; are provided and may be used for, among other uses, the expression of a p53UBC polypeptide which can be used as an immunogen, immunological reagent, and the like. Such polynucleotides typically comprise an operably linked promoter for driving expression in a suitable prokaryotic or eukaryotic host cell. One exemplification of such a polynucleotide is the human p53UBC cDNA sequence of Fig. 2 cloned in operable linkage to the mammalian expression vector pSR , many alternative embodiments will be apparent to those of skill in the art, including the use of alternative expression vectors (e.g., pBC12BI and p91023(B) ; Hanahan J (1983) J. Mol. Biol. 166: 577; Cullen et al. (1985) J. Virol. 53: 515; Lomedico PT (1982) Proc. Natl. Acad. Sci. (U.S.A.) 79: 5798; Morinaga et al. (1984) Bio/Technology 2 : 636) . Additionally, where expression of a polypeptide is not desired, polynucleotides of this invention need not encode a functional protein. Polynucleotides of this invention may serve as hybridization probes and/or PCR primers (amplimers) and/or LCR oligomers for detecting p53UBC RNA or DNA sequences. Alternatively, polynucleotides of this invention may serve as hybridization probes or primers for detecting RNA or DNA sequences of related genes, such genes may encode structurally or evolutionarily related proteins. For such hybridization and PCR applications, the polynucleotides of the invention need not encode a functional polypeptide. Thus, polynucleotides of the invention may contain substantial deletions, additions, nucleotide substitutions and/or transpositions, so long as specific hybridization or specific amplification to the p53UBC sequence is retained. Specific hybridization is defined hereinbefore, and can be roughly summarized as the formation of hybrids between a polynucleotide of the invention (which may include substitutions, deletions, and/or additions) and a specific target polynucleotide such as human p53UBC mRNA so that a single band is identified corresponding to each p53UBC isoform on a Northern blot of RNA prepared from p53£7BC-expressing cells (i.e., hybridization and washing conditions can be established that permit detection of discrete p53UBC mRNA band(s)) . Thus, those of ordinary skill in the art can prepare polynucleotides of the invention, which may include substantial additions, deletions, substitutions, or transpositions of nucleotide sequence as compared to sequences shown in Figs. 1A-1D and determine whether specific hybridization is a property of the polynucleotide by performing a Northern blot using RNA prepared from a cell line which expresses p53UBC mRNA and/or by hybridization to a p53UBC DNA clone (cDNA or genomic clone) . Specific amplification is defined as the ability of a set of PCR amplimers, when used together in a PCR reaction with a p53UBC polynucleotide, to produce substantially a single major amplification product which corresponds to a p53UBC gene sequence or mRNA sequence. Generally, human genomic DNA or mRNA from p53UBC expressing human cells is used as the template DNA sample for the PCR reaction. PCR amplimers that exhibit specific amplification are suitable for quantitative determination of p53UBC mRNA by quantitative PCR amplification. p53UBC allele-specific amplification products, although having sequence and/or length polymorphisms, are considered to constitute a single amplification product for purposes of this definition. Generally, hybridization probes comprise approximately at least 25 consecutive nucleotides of a sequence shown in Fig. 2 (for human p53-interacting polypeptide detection, respectively) , preferably the hybridization probes contain at least 50 consecutive nucleotides of a sequence shown in Fig. 2, and more preferably comprise at least 100 consecutive nucleotides of a sequence shown in Fig. 2. PCR amplimers typically comprise approximately 25 to 50 consecutive nucleotides of a sequence shown in Fig. 2, and usually consist essentially of approximately 25 to 50 consecutive nucleotides of a sequence shown in Fig. 2 with additional nucleotides, if present, generally being at the 5 ' end so as not to interfere with polymerase-mediated chain extension. PCR amplimer design and hybridization probe selection are well within the scope of discretion of practioners of ordinary skill in the art. WBPl and p53UBC polynucleotides have many utilities, including but not limited to their use as viscosity-enhancing solutes (typically WBPl and p53UBC polynucleotides of 25- 100,000 nucleotides or more are dissolved in an aqueous solvent, such as PBS, to produce a solution having substantial viscosity or as carrier polynucleotides to co-precipitate other polynucleotide species present in solution at low abundance) , their use as nutritive foodstuffs, their use as a combustible energy source, and other uses described herein or apparent to the practitioner. Methods Relating to Genetic Disease In one preferred embodiment of the invention, hybridization probes that specifically identify the WBPl or p53UBC gene may be used in methods for diagnosing genetic disease. For example, but not for limitation, the genetic disease thus diagnosed may involve a les-ion in the relevant WBPl or p53UBC structural or regulatory sequences, or may involve a lesion in a genetic locus closely linked to the IVBP1 or p53UBC locus and which can be identified by restriction fragment length polymorphism or DNA sequence polymorphism at the linked WBPl or p53UBC locus. In a further preferred embodiment, WBPl or p53UBC gene probes are used to diagnose or identify genetic disease involving predisposition to immunological disease, wherein the amount or functionality of endogenous WBPl or p53UBC is sufficient for the individual to exhibit an increased probability of developing a disease, particularly a disease of cell proliferation (e.g., neoplasia, senescence, wound healing) , arthritis, or autoimmune disease. Antisense Polynucleotides Additional embodiments directed to modulation of p53 functional activity include methods that employ specific antisense polynucleotides complementary to all or part of the sequences shown in Figs. 1A-1D or Fig. 2. Such complementary antisense polynucleotides may include nucleotide substitutions, additions, deletions, or transpositions, so long as specific hybridization to the relevant target sequence corresponding to Figs. 1A-1D or Fig. 2 is retained as a functional property of the polynucleotide. Complementary antisense polynucleotides include soluble antisense RNA or DNA oligonucleotides which can hybridize specifically to iVBPl or p53UBC mRNA species and prevent transcription of the mRNA species and/or translation of the encoded polypeptide (Ching et al. (1989) Proc. Natl. Acad. Sci. U.S.A. 86: 10006; Broder et al. (1990) Ann. Int. Med. 113: 604; Loreau et al. (1990) FEBS Letters 274: 53; Holcenberg et al., W091/11535; U.S.S.N. 07/530,165; WO91/09865; WO91/04753; WO90/13641; and EP 386563, each of which is incorporated herein by reference) . The antisense polynucleotides therefore inhibit production of 1VBP1 or p53UBC polypeptides. Since WBPl or p53UBC protein expression is associated with p53 binding and function, antisense polynucleotides that prevent transcription and/or translation of mRNA corresponding to WBPl or p53UBC polypeptides may modulate p53 function and/or reverse the p53 phenotype of cells. Compositions containing a therapeutically effective dosage of WBPl or p53UBC antisense polynucleotides may be administered for treatment of diseases, including neoplasia, hyperplasia, wound healing, inflammation, and for inhibition of transplant rejection reactions, and the like, if desired. Antisense polynucleotides of various lengths may be produced, although such antisense polynucleotides typically comprise a sequence of about at least 25 consecutive nucleotides which are substantially identical to a naturally- occurring WBPl or p53UBC polynucleotide sequence, and typically which are identical to a sequence shown in Figs. 1A- 1D or Fig. 2. Antisense polynucleotides may be produced from a heterologous expression cassette in a transfectant cell or transgenic cell, such as a transgenic pluripotent hematopoietic stem cell used to reconstitute all or part of the hematopoietic stem cell population of an individual. Alternatively, the antisense polynucleotides may comprise soluble oligonucleotides that are administered to the external milieu, either in the culture medium in vitro or in the circulatory system or interstitial fluid in vivo. Soluble antisense polynucleotides present in the external milieu have been shown to gain access to the cytoplasm and inhibit translation of specific mRNA species. In some embodiments the antisense polynucleotides comprise methylphosphonate moieties. For general methods relating to antisense polynucleotides, see Antisense RNA and DNA, (1988) , D.A. Melton, Ed., Cold Spring Harbor Laboratory, Cold Spring Harbor, NY) . The antisense polynucleotides may comprise phosphordithiolate DNA (Marshall WS and Caruthers MH (1993) Science 259: 1564) , peptide nucleic acids (Egholm et al. (1992) J. Am. Chem. Soc. 114: 1895; Hanvey et al. (1992) Science 258: 1481), and other polynucleotide-mi etic chemical architectures known or apparent to those of skill in the art. Isolation of the Cognate Human WBPl and p53UBC Genes The human homolog of the WBPl and p53UBC cDNA sequences are identified and isolated by screening a human genomic clone library, such as a human genomic library in yeast artificial chromosomes, cosmids, or bacteriophage λ (e.g., λ Charon 35), with a polynucleotide probe comprising a sequence of about at least 24 contiguous nucleotides (or their complement) of the cDNA sequence shown in Figs. 1A-1D or Fig. 2, respectively. Typically, hybridization and washing conditions are performed at high stringency according to conventional hybridization procedures. Positive clones are isolated and sequenced. For illustration and not for limitation, a full-length polynucleotide corresponding to the sequence of Figs. 1A-1D or Fig. 2 may be labeled and used as a hybridization probe to isolate genomic clones from a human or murine genomic clone library in λEMBL4 or λGEMll (Promega Corporation, Madison, Wisconsin) ; typical hybridization conditions for screening plaque lifts (Benton and Davis (1978) Science 196: 180) can be: 50% formamide, 5 x SSC or SSPE, 1-5 x Denhardt's solution, 0.1-1% SDS, 100-200 μg sheared heterologous DNA or tRNA, 0-10% dextran sulfate, 1 xlO 5 to 1 x 10 7 cpm/ml of denatured probe with a specific activity of about 1 x 10 8 cpm/μg, and incubation at 42°C for about 6-36 hours. Prehybridization conditions are essentially identical except that probe is not included and incubation time is typically reduced. Washing conditions are typically 1-3 x SSC, 0.1-1% SDS, 50-70°C with change of wash solution at about 5-30 minutes. Nonhuman WBPl or p53UBC cDNAs and genomic clones (i.e., cognate nonhuman WBPl or p53UBC genes) can be analogously isolated from various nonhuman cDNA and genomic clone libraries available in the art (e.g., Clontech, Palo Alto, CA) by using probes based on the sequences shown in Fig. 1, with hybridization and washing conditions typically being less stringent than for isolation of human WBPl or p53UBC clones. Polynucleotides comprising sequences of approximately at least 30-50 nucleotides, preferably at least 100 nucleotides, corresponding to or complementary to the nucleotide sequences shown in Figs. 1A-1D or Fig. 2 can serve as PCR primers and/or hybridization probes for identifying and isolating germline genes corresponding to IVBP1 or p53UBC, respectively. These germline genes may be human or may be from a related mammalian species, preferably rodents or primates. Such germline genes may be isolated by various methods conventional in the art, including, but not limited to, by hybridization screening of genomic libraries in bacteriophage λ or cosmid libraries, or by PCR amplification of genomic sequences using primers derived from the sequences shown in Figs. 1A-1D or Fig. 2. Human genomic libraries are publicly available or may be constructed de novo from human DNA. Genomic clones of WBPl or p53UBC, particularly of the murine cognate WBPl or p53UBC gene, may be used to construct homologous targeting constructs for generating cells and transgenic nonhuman animals having at least one functionally disrupted WBPl or p53UBC allele, preferably homozygous for knocked out WBPl or p53UBC alleles. Guidance for construction of homologous targeting constructs may be found in the art, including: Rahemtulla et al. (1991) Nature 353: 180; Jasin et al. (1990) Genes Devel. 4.: 157; Koh et al. (1992) Science 256: 1210; Molina et al. (1992) Nature 357: 161; Grusby et al. (1991) Science 253 : 1417; Bradley et al. (1992) Bio/Technology 10: 534, incorporated herein by reference) . Homologous targeting can be used to generate so- called "knockout" mice, which are heterozygous or homozygous for an inactivated WBPl or p53UBC allele. Such mice may be sold commercially as research animals for investigation of apoptosiε, neoplasia, cell proliferation, signal tranεduction, drug screening, and other uses. Chimeric targeted mice are derived according to Hogan, et al., Manipulating the Mouse Embryo: A Laboratory Manual, Cold Spring Harbor Laboratory (1988) and Teratocarcinomas and Embryonic Stem Cells: A Practical Approach, E.J. Robertson, ed. , IRL Press, Washington, D.C., (1987) which are incorporated herein by reference. Embryonic stem cells are manipulated according to published procedures (Teratocarcinomas and Embryonic Stem Cells: A Practical Approach, E.J. Robertson, ed. , IRL Press, Washington, D.C. (1987); Zjilstra et al. (1989) Nature 342:435; and Schwartzberg et al. (1989) Science 246: 799, each of which is incorporated herein by reference) . Additionally, a WBPl or p53UBC cDNA or genomic gene copy may be used to construct transgenes for expressing WBPl or p53UBC polypeptides at high levels and/or under the transcriptional control of transcription control sequences which do not naturally occur adjacent to the WBPl or p53UBC gene. For example but not limitation, a constitutive promoter (e.g., a HSV-t/ or pgk promoter) or a cell-lineage specific transcriptional regulatory sequence (e.g., a CD4 or CD8 gene promoter/enhancer) may be operably linked to a WBPl- or p5 UBC-encoding polynucleotide sequence to form a transgene (typically in combination with a selectable marker such as a neo gene expression cassette) . Such transgenes can be introduced into cells (e.g., ES cells, hematopoietic stem cells, cultured primary hepatocytes) and transgenic cells and transgenic nonhuman animals may be obtained according to conventional methods. Transgenic cells and/or transgenic nonhuman animals may be used to screen for antineoplastic agents and/or to screen for potential cell proliferation modulating agents, as overexpression of WBPl or p53UBC or inappropriate expression of WBPl or p53UBC may result in a hyperproliferative state or hypoproliferative state. Identification of Proteins That Bind WBPl or p53UBC Proteins that bind to WBPl or p53UBC are potentially important regulatory proteins. Such proteins may be targets for novel therapeutic agents. These proteins are referred to herein as accessory proteins. For purposes of this invention, p53 is defined as not being an accessory protein of WBPl or p53UBC, although p53 polypeptide sequences bind to WBPl and p53UBC polypeptides in a yeast two-hybrid system. Accessory proteins may be isolated by various methods known in the art. One preferred method of isolating accessory proteins is by contacting a WBPl or p53UBC polypeptide to an antibody that binds the WBPl or p53UBC polypeptide, and isolating resultant immune complexes. These immune complexes may contain accessory proteins bound to the WBPl or p53UBC polypeptide. The accessory proteins may be identified and isolated by denaturing the immune complexes with a denaturing agent and, preferably, a reducing agent. The denatured, and preferably reduced, proteins can be electrophoresed on a polyacrylamide gel. Putative accessory proteins can be identified on the polyacrylamide gel by one or more of various well known methods (e.g., Coomassie staining, Western blotting, silver staining, etc.) , and isolated by resection of a portion of the polyacrylamide gel containing the relevant identified polypeptide and elution of the polypeptide from the gel portion. A putative accessory protein may be identified as an accessory protein by demonstration that the protein binds to WBPl or p53UBC protein. Such binding may be shown in vitro by various means, including, but not limited to, binding assays employing a putative accessory protein that has been renatured subsequent to isolation by a polyacrylamide gel electrophoresis method. Alternatively, binding assays employing recombinant or chemically synthesized putative accessory protein may be used. For example, a putative accessory protein may be isolated and all or part of its amino acid sequence determined by chemical sequencing, such as Edman degradation. The amino acid sequence information may be used to chemically synthesize the putative accessory protein. The amino acid sequence may also be used to produce a recombinant putative accessory protein by: (1) isolating a cDNA clone encoding the putative accessory protein by screening a cDNA library with degenerate oligonucleotide probes according to the amino acid sequence data, (2) expressing the cDNA in a host cell, and (3) isolating the putative accessory protein. Alternatively, a polynucleotide encoding a WBPl or p53UBC polypeptide may be constructed by oligonucleotide synthesis, placed in an expression vector, and expressed in a host cell. Putative accessory proteins that bind WBPl and/or p53UBC in vitro are identified as accessory proteins. Accessory proteins may also be identified by crosslinking in vivo with bifunctional crosslinking reagents (e.g., dimethylsuberimidate, glutaraldehyde, etc.) and subsequent isolation of crosslinked products that include a WBPl or p53UBC polypeptide. For a general discussion of cross- linking, see Kunkel et al. (1981) Mol. Cell. Biochem. 34: 3, which is incorporated herein by reference. Preferably, the bifunctional crosslinking reagent will produce crosslinks which may be reversed under specific conditions after isolation of the crosslinked complex so as to facilitate isolation of the accessory protein from the WBPl or p53UBC polypeptide. Isolation of crosslinked complexes that include a WBPl or p53UBC polypeptide is preferably accomplished by binding an antibody that binds a WBPl or p53UBC polypeptide with an affinity of at least 1 x 10 7 M -1 to a population of crosslinked complexes and recovering only those complexes that bind to the antibody with an affinity of at least 1 x 10 7 M -1 . Polypeptides that are crosslinked to a WBPl or p53UBC polypeptide are identified as accessory proteins. Screening assays can be developed for identifying candidate immunomodulatory agents as being agents which inhibit binding of WBPl or p53UBC to an accessory protein under suitable binding conditions. Expression of WBPl and p53UBC Polypeptides The nucleic acid sequences of the present invention capable of ultimately expressing the desired WBPl or p53UBC polypeptides can be formed from a variety of different polynucleotides (genomic or cDNA, RNA, synthetic oligonucleotides, etc.) as well as by a variety of different techniques. As stated previously, the DNA sequences will be expressed in hosts after the sequences have been operably linked to (i.e. , positioned to ensure the functioning of) an expression control sequence. These expression vectors are typically replicable in the host organisms either as episomes or as an integral part of the host chromosomal DNA. Commonly, expression vectors will contain selection markers, e.g. , tetracycline resistance or hygromycin resistance, to permit detection and/or selection of those cells transformed with the desired DNA sequences (see, e.g. , U.S. Patent 4,704,362, which is incorporated herein by reference) . E. coli is one prokaryotic host useful particularly for cloning the DNA sequences of the present invention. Other microbial hosts suitable for use include bacilli, such as Bacillus subtilis, and other Enterobacteriaceae, such as Salmonella, Serratia, and various Pseudomonas species. In these prokaryotic hosts, one can also make expression vectors, which will typically contain expression control sequences compatible with the host cell (e.g.. an origin of replication) . In addition, any number of a variety of well- known promoters will be present, such as the lactose promoter system, a tryptophan (trp) promoter system, a beta-lactamase promoter system, or a promoter system from phage lambda. The promoters will typically control expression, optionally with an operator sequence, and have ribosome binding site sequences and the like, for initiating and completing transcription and translation. Other microbes, such as yeast, may also be used for expression. Saccharomyces is a preferred host, with suitable vectors having expression control sequences, such as promoters, including 3-phosphoglycerate kinase or other glycolytic enzymes, and an origin of replication, termination sequences and the like as desired. In addition to microorganisms, mammalian tissue cell culture may also be used to express and produce the polypeptides of the present invention (see, Winnacker, "From Genes to Clones," VCH Publishers, N.Y., N.Y. (1987), which is incorporated herein by reference) . Eukaryotic cells are actually preferred, because a number of suitable host cell lines capable of secreting intact human proteins have been developed in the art, and include the CHO cell lines, various COS cell lines, HeLa cells, myeloma cell lines, Jurkat cells, etc. Expression vectors for these cells can include expression control sequences, such as an origin of replication, a promoter, an enhancer (Queen et al. (1986) Immunol. Rev. 89 : 49, which is incorporated herein by reference) , and necessary processing information sites, such as ribosome binding sites, RNA splice sites, polyadenylation sites, and transcriptional terminator sequences. Preferred expression control sequences are promoters derived from immunoglobulin genes, SV40, adenovirus, bovine papillomavirus, and the like. The vectors containing the DNA segments of interest (e.g. , polypeptides encoding a WBPl or p53UBC polypeptide) can be transferred into the host cell by well- known methods, which vary depending on the type of cellular host. For example, CaCl transfection is commonly utilized for prokaryotic cells, whereas CaP0 4 treatment or electroporation may be used for other cellular hosts. (See, generally, Maniatis, et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Press, (1982) , which is incorporated herein by reference) . Usually, vectors are episomes and are maintained extrachromosomally. Expression of recombinant WBPl or p53UBC protein in cells, may be used to identify and isolate genes that are transcriptionally modulated, either positively or negatively, by the presence of WBPl or p53UBC protein, either directly or via its interaction with p53. Such genes are typically initially identified as cDNA clones isolated from subtractive cDNA libraries, wherein RNA isolated from cells expressing recombinant WBPl or p53UBC and RNA isolated from control cells (i.e., not expressing recombinant IVBP1 or p53UBC) are used to generate the subtractive libraries and screening probes. In such a manner, WBPl- or p53C7BC-dependent genes may be isolated. WBPl- or p53UBC-dependent genes (or their regulatory sequences operably linked to a reporter gene) may be used as a component of an in vitro transcription assay. Methods for Forensic Identification The WBPl or p53UBC polynucleotide sequences of the present invention can be used for forensic identification of individual humans, such as for identification of decedents, determination of paternity, criminal identification, and the like. For example but not limitation, a DNA sample can be obtained from a person or from a cellular sample (e.g. , crime scene evidence such as blood, saliva, semen, and the like) and subjected to RFLP analysis, allele-specific PCR, or PCR cloning and sequencing of the amplification product to determine the structure of the WBPl or p53UBC gene region. On the basis of the WBPl or p53UBC gene structure, the individual from which the sample originated will be identified with respect to his/her WBPl or p53UBC genotype. The WBPl or p53UBC genotype may be used alone or in conjunction with other genetic markers to conclusively identify an individual or to rule out the individual as a possible perpetrator. In one embodiment, human genomic DNA samples from a population of individuals (typically at least 50 persons from various racial origins) are individually aliquoted into reaction vessels (e.g., a well on a microtitre plate) . Each aliquot is digested (incubated) with one or more restriction enzymes (e.g., EcoRI, Hindlll, Smal, BamHI, Sail, Notl, Accl, Apal, Bglll, Xbal, Pstl) under suitable reaction conditions (e.g., see New England Biolabs or ProMega 1993 catalogs) . Corresponding digestion products from each individual are loaded separately on an electrophoretic gel (typically agarose) , electrophoresed, blotted to a membrane by Southern blotting, and hybridized with a labeled WBPl or p53UBC probe (e.g., a sequence of Figs. 1A-1D or Fig. 2) . Restriction fragments (bands) which are polymorphic among members of the population are used as a basis to discriminate WBPl or p53UBC genotypes and thereby classify individuals on the basis of their WBPl or p53UBC genotype. Similar categorization of WBPl or p53UBC genotypes may be performed by sequencing PCR amplification products from a population of individuals and using sequence polymorphisms to identify alleles (genotypes) , and thereby identify or classify individuals. Yeast Two-Hybrid Screening Assays Yeast two-hybrid systems may be used to screen a mammalian (typically human) cDNA expression library, wherein cDNA is fused to a GAL4 DNA binding domain or activator domain, and a WBPl or p53UBC polypeptide sequence is fused to a GAL4 activator domain or DNA binding domain, respectively. Such a yeast two-hybrid system can screen for cDNAs encoding proteins which bind to WBPl or p53UBC sequences. For example, a cDNA library can be produced from mRNA from a human cell line or other suitable cell type. Such a cDNA library cloned in a yeast two-hybrid expression system (Chien et al. (1991) Proc. Natl. Acad. Sci. (U.S.A.) 88: 9578; Zervos et al. (1993) Cell 72: 233) can be used to identify cDNAs which encode proteins that interact with WBPl or p53UBC and thereby produce expression of the GAL4-dependent reporter gene. Polypeptides which interact with WBPl or p53UBC can also be identified by immunoprecipitation of WBPl or p53UBC with antibody and identification of co-precipitating species. Further, polypeptides that bind IVBP2 or p53UBC can be identified by screening a peptide library (e.g., a bacteriophage peptide display library, a spatially defined VLSIPS peptide array, and the like) with a WBPl or p53UBC polypeptide. Methods for Rational Drug Design WBPl or p53UBC polypeptides, especially those portions which form direct contacts in p53 complexes, can be used for rational drug design of candidate p53-modulating agents (e.g., antineoplastics and p53 modulators). The substantially purified WBPl or p53UBC protein and the identification of p53 as a docking partner for WBPl and p53UBC as provided herein permits production of substantially pure WBPl :p53 and p53UBC:p53 polypeptide complexes and computational models which can be used for protein X-ray crystallography or other structure analysis methods, such as the DOCK program (Kuntz et al. (1982) J. Mol. Biol. 161: 269; Kuntz ID (1992) Science 257: 1078) and variants thereof. Potential therapeutic drugs may be designed rationally on the basis of structural information thus provided. In one embodiment, such drugs are designed to prevent formation of a WBPl : p53 or p53UBC: p53 polypeptide complexes. Thus, the present invention may be used to design drugs, including drugs with a capacity to inhibit binding of WBPl or p53UBC to p53 . Methods of Identifying Novel p53-Modulating Agents A basis of the present invention is the experimental finding that WBPl and p53UBC polypeptides binds specifically to p53, a protein known to modulate cell proliferation in cells and which is known to be bound (sequestered) by viral- encoded oncogenic proteins. For example, agents which block p53 function and/or block WBPl or p53UBC function may be developed as potential human therapeutic drugs. Candidate therapeutic agents are then tested further for antineoplastic activity or cell proliferation enhancement activity in assays which are routinely used to predict suitability for use as human antineoplastic drugs. Examples of these assays include, but are not limited to: (1) ability of the candidate agent to inhibit the ability of anchorage- independent transformed cells to grow in soft agar, (2) ability to reduce tumorigenicity of transformed cells transplanted into nu/nu mice, (3) ability to reverse morphological transformation of transformed cells, (4) ability to reduce growth of transplanted tumors in nu/nu mice, (5) ability to inhibit formation of tumors or preneoplastic cells in animal models of spontaneous or chemically-induced carcinogenesis, and (6) ability to induce a more differentiated phenotype in transformed cells to which the agent is applied. WBPl : p53 and p53UBC: p53 Intermolecular Binding A basis of the present invention is the surprising finding that the WBPl and p53UBC protein sequences form a complex with the p53 protein under physiological conditions. This finding indicates that the WBPl and p53UBC proteins serve as a modulators of p53 function, and vice versa. Such functional modulation can serve to couple a signal transduction pathway (via WBPl or p53UBC) to an cell proliferation regulatory protein (i.e., p53 ) . Assays for detecting the ability of agents to inhibit the binding of WBPl or p53UBC to p53 provide for facile high-throughput screening of agent banks (e.g., compound libraries, peptide libraries, and the like) to identify WBPl or p53UBC (or p53 ) antagonists or agonists. Such WBPl or p53UBC (or p53 ) antagonists and agonists may modulate P7BP2 or p53UBC (or p53 ) activity and thereby modulate cell proliferation and neoplasia. Administration of an efficacious dose of an agent capable of specifically inhibiting WBPl : p53 or p53UBC:p53 complex formation or p53 : p53 complex formation to a patient can be used as a therapeutic or prophylactic method for treating pathological conditions (e.g., cancer, inflammation, proliferative diseases, autoimmune disease, and the like) which are effectively treated by modulating WBPl and/or p53UBC and/or p53 activity and cell proliferation. Binding assays generally take one of two forms: immobilized p53-interacting polypeptide(s) can be used to bind labeled p53 polypeptide(s) , or conversely, immobilized p53 polypeptide(s) can be used to bind labeled WBPl or p53UBC polypeptides. Alternatively, a binding assay can be performed to detect binding of a WBPl or p53UBC polypeptide to form homodimers. Typically, a labeled WBPl or p53UBC polypeptide is contacted with an immobilized p53 polypeptide under aqueous binding conditions and the extent of binding is determined by measuring the amount of immobilized labeled p53 . In each case, the labeled polypeptide is contacted with the immobilized polypeptide under aqueous conditions that permit specific binding of the polypeptides(s) to form a p53 :p53- interacting polypeptide complex in the absence of added agent. Particular aqueous conditions may be selected by the practitioner according to conventional methods. For general guidance, the following buffered aqueous conditions may be used: 10-250 mM NaCl, 5-50 mM Tris HCI, pH 5-8, with optional addition of divalent cation(s) and/or metal chelators and/or nonionic detergents and/or membrane fractions. It is appreciated by those in the art that additions, deletions, modifications (such as pH) and substitutions (such as KC1 substituting for NaCl or buffer substitution) may be made to these basic conditions. Modifications can be made to the basic binding reaction conditions so long as specific binding of WBPl or p53UBC polypeptide(s) to p53 polypeptides occurs in the control reaction(s) . In some embodiments, where the assay detects formation of homodimers, modifications can be made to the basic binding reaction conditions so long as specific binding of a WBPl , p53UBC, or p53 polypeptide to form homodimers occurs in the control reaction(s) . Conditions that do not permit specific binding in control reactions (no agent included) are not suitable for use in binding assays. Preferably, at least one polypeptide species is labeled with a detectable marker. Suitable labeling includes, but is not limited to, radiolabeling by incorporation of a radiolabeled amino acid (e.g., 14 C-labeled leucine, 3 H-labeled glycine, 35 S-labeled methionine) , radiolabeling by post- translational radioiodination with 125 ι or 131 ι (e.g., Bolton- Hunter reaction and chloramine T) , labeling by post- translational phosphorylation with 3 P (e.g., phosphorylase and inorganic radiolabeled phosphate) fluorescent labeling by incorporation of a fluorescent label (e.g., fluorescein or rhodamine) , or labeling by other conventional methods known in the art. In embodiments where one of the polypeptide species is immobilized by linkage to a substrate, the other polypeptide is generally labeled with a detectable marker. Additionally, in some embodiments a WBPl , p53UBC, or p53 polypeptide may be used in combination with an accessory protein (e.g., a protein which forms a complex with the polypeptide in vivo) , it is preferred that different labels are used for each polypeptide species, so that binding of individual and/or heterodimeric and/or multimeric complexes can be distinguished. For example but not limitation, a WBPl or p53UBC polypeptide may be labeled with fluorescein and an accessory polypeptide may be labeled with a fluorescent marker that fluorescesces with either a different excitation wavelength or emission wavelength, or both. Alternatively, double-label scintillation counting may be used, wherein a WBPl or p53UBC polypeptide is labeled with one isotope (e.g., 3 H) and a second polypeptide species is labeled with a different isotope (e.g., 14 C) that can be distinguished by scintillation counting using discrimination techniques. Labeled polypeptide(s) are contacted with immobilized polypeptid (s) under aqueous conditions as described herein. The time and temperature of incubation of a binding reaction may be varied, so long as the selected conditions permit specific binding to occur in a control reaction where no agent is present. Preferable embodiments employ a reaction temperature of about at least 15 degrees Centigrade, more preferably 35 to 42 degrees Centigrade, and a time of incubation of approximately at least 15 seconds, although longer incubation periods are preferable so that, in some embodiments, a binding equilibrium is attained. Binding kinetics and the thermodynamic stability of bound p53 :p53- interacting polypeptide complexes determine the latitude available for varying the time, temperature, salt, pH, and other reaction conditions. However, for any particular embodiment, desired binding reaction conditions can be calibrated readily by the practitioner using conventional methods in the art, which may include binding analysis using Scatchard analysis, Hill analysis, and other methods (Proteins, Structures and Molecular Principles, (1984) Creighton (ed.), W.H. Freeman and Company, New York). Specific binding of labeled WBPl or p53UBC polypeptide to immobilized p53 polypeptide, respectively, is determined by including unlabeled competitor protein(s) (e.g., albumin) . After a binding reaction is completed, labeled polypeptide(s) that is/are specifically bound to immobilized polypeptide is detected. For example and not for limitation, after a suitable incubation period for binding, the aqueous phase containing non-immobilized protein is removed and the substrate containing the immobilized polypeptide species and any labeled protein bound to it is washed with a suitable buffer, optionally containing unlabeled blocking agent(s), and the wash buffer(ε) removed. After washing, the amount of detectable label remaining specifically bound to the immobilized polypeptide is determined (e.g., by optical, enzymatic, autoradiographic, or other radiochemical methods) . In some embodiments, addition of unlabeled blocking agents that inhibit non-specific binding are included. Examples of such blocking agents include, but are not limited to, the following: calf thymus DNA, salmon sperm DNA, yeast RNA, mixed sequence (random or pseudorandom sequence) oligonucleotides of various lengths, bovine serum albumin, nonionic detergents (NP-40, Tween, Triton X-100, etc.), nonfat dry milk proteins, Denhardt's reagent, polyvinylpyrrolidone, Ficoll, and other blocking agents. Practitioners may, in their discretion, select blocking agents at suitable concentrations to be included in binding assays; however, reaction conditions are selected so as to permit specific binding between a WBPl or p53UBC polypeptide and a p53 polypeptide in a control binding reaction. Blocking agents are included to inhibit nonspecific binding of labeled protein to immobilized protein and/or to inhibit nonspecific binding of labeled polypeptide to the immobilization substrate. In embodiments where a polypeptide is immobilized, covalent or noncovalent linkage to a substrate may be used. Covalent linkage chemistries include, but are not limited to, well-characterized methods known in the art (Kadonaga and Tijan (1986) Proc. Natl. Acad. Sci. (U.S.A.) 83: 5889, which iε incorporated herein by reference) . One example, not for limitation, is covalent linkage to a substrate derivatized with cyanogen bromide (such as CNBr-derivatized Sepharose 4B) . It may be desirable to use a spacer to reduce potential steric hindrance from the substrate. Noncovalent bonding of proteins to a substrate include, but are not limited to, bonding of the protein to a charged surface and binding with specific antibodies. In one class of embodiments, parallel binding reactions are conducted, wherein one set of reactions serves as control and at least one other set of reactions include various quantities of agents, mixtures of agents, or biological extracts, that are being tested for the capacity to inhibit binding of a p53-interacting polypeptide to a p53 polypeptide, and/or to inhibit binding of a WBPl , p53UBC, or p53 polypeptides to form homomultimers (homodimers) . The following examples are offered by way of example and not by way of limitation. Variations and alternate embodimentε will be apparent to thoεe of skill in the art. EXPERIMENTAL EXAMPLES EXAMPLE 1. Determination of the nucleotide and deduced amino acid sequence of human cDNAs encoding p53-binding proteins This example describes the identification of human cDNAs that encode p53-binding proteins active in a yeast two- hybrid screening system. Cloned polynucleotides were isolated from a yeast two-hybrid screening system comprising a polynucleotide encoding a human p53 polypeptide sequence fused to a GAL4 {INVENTORS: activation domain or DNA-binding domain ???} and a polynucleotide encoding a human cDNA library sequence fused to a {INVENTORS: activation domain or DNA-binding domain ???}. The yeast two hybrid system contained (1) a cDNA library derived from HeLa cells that had been cloned into the GAL4 plasmid pGAD, deεcribed in Chien et al. (1991) op.cit and (2) a polynucleotide εequence encoding a human p53 polypeptide spanning from amino acid 72 to amino acid 393 of a wild-type human p53 polypeptide sequence cloned into the GAL4 plasmid pGBT8, described in Freed et al. (1994) Science 265: 1713. Colonies were identified as positive by growth on minimal medium containing adenine and lacking tryptophan, leucine, and histidine. Positive colonies were selected and the polynucleotide sequence of the cDNA insert was isolated. For WBPl , the cDNA inεert was isolated by digestion with EcoRI and Xhol, the EcoRI/Xbal fragment cloned into pBluescript, and sequenced by Sanger dideoxy sequencing. For p53UBC, the cDNA inεert waε iεolated by digeεtion with BamHI and Smal, the BamHI/Smal fragment cloned into pBluescript, and sequenced by Sanger dideoxy sequencing. Two positive clones were isolated and sequenced. WBPl One clone, designated clone 85 (1VBP2) , specifically binds a conformationally wild-type human p53 and substantially lacks binding to mutant p53 proteins that have a pAb240 epitope. The pAB240 monoclonal antibody specifically recognizes a common conformational change found in many mutant p53 polypeptides. Wild-type human p53 comprised amino acids 72-393 of human p53 , and mutant human p53 comprised that sequence with a point mutation at amino acid #141 (Cys—>Arg) or at amino acid # 175 (Arg—>His) . The nucleotide and deduced amino acid sequences of WBPl are shown in Figs. 1A-1D. A region of 152 amino acids encoded by clone WBPl waε found to be sufficient to bind wild- type human p53 in vitro. Full-length WBPl and various deletions were transcribed and translated in vitro in the presence of 35 S-methionine and mixed with wild-type p53 (purified from a baculovirus expreεεion system) . The mixture was incubated at 4°C for three hours, whereupon a monoclonal antibody (pAB421) that binds p53 and Protein A-Sepharose beads were added, and the incubation was continued for an additional hour at 4°C. The Protein A-Sepharose immune complexes were recovered and washed three times with 20 mM Tris (pH 8.0), 150 mM NaCl, 0.1% NP-40, and dissolved in SDS-gel sample buffer for SDS-PAGE. The samples were resolved on an 11 percent polyacrylamide gel containing SDS. Interaction with p53 was scored by the ability of the p53-specific monoclonal antibody pAB421 to immunoprecipitate the WBPl polypeptide being tested. These experiments demonstrated that a 152 amino acid εegment of the WBPl protein (encoded by the approximately 450 nucleotide Pstl fragment) was sufficient to confer the property of binding to p53 in vitro. This fragment has the sequence: ELPHLTSALHPVHPDIKLQKLPFYDLLDELIKPTSLASDNSQRFRETCFAFALTPQQVQQ ISSSMDISGTKCDFTVQVQLRFCLSETSCPQEDHFPPNLCVKVNTKPCSLPGYLPPTKNG VEPKRPSRPINITSLVRLSTTVPNTIWSWTA. Sequence analysis of WBPl revealed partial identity with HFBDQ46 (Nature Genetics (1993) 4_: 256), a randomly isolated 351 bp cDNA of unknown function obtained for use aε a genetic marker (i.e., an expressed sequence tag) . The εegmerc of WBPl εpanning from nucleotide 201 to nucleotide 599 was aligned to the complete sequence of HFBDQ46 (designated T06215) and is shown below (top sequence is WBPl , bottom sequence is HFBDQ46: 201 CACAGAAAATCATGACGCCTGCAGACTTGTCCATCCCCAACGTACATTCA 250 I I I I I I I I I I I I I I 1 I I I I I 1 I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I I I 1 CTGACTTGTCCATCCCCAACGTACATTCA 29 251 AGTCCTATGCCAGCAACTTTGTCTCCATCTACCATTCCACAACTCACTTA 300 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 30 AGTCCTATGCCAGCAACTTTGTCTCCATCTACCATTCCACAACTCACTTA 79 301 CGATGGTCACCCTGCATCATCGCCATTACTCCCTGTTTCTCTTCTGGGAC 350 I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I I I 80 CGATGGTCACCCTGCATCATCGCCATTACTCCCTGTTTCTCTTCTGGGAC 129 351 CTAAACATGAACTGGAACTCCCACATCTTACATCAGCTCTTCACCCAGTC 400 I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 130 CTAAACATGAACTGGAACTCCCACATCTTACATCAGCTCTTCACCCAGTC 179 401 CATCCGGATATAAAACTTCAAAAATTACCATTTTATGATTTACTGGATGA 450 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I 180 CATCCGGATATAAAACTTCAAAAATTACCATTTTATGATTTACTGGATGA 229 451 ACTGATAAAACCCACCAGTCTAGCATCAGACAACAGTCAGCGCTTTCGAG 500 I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I I I 230 ACTGATAAAACCCACCAGTCTAGCATCAGACAACAGTCAGCGCTTTCGAG 279 501 AAACCTGTTTTGCATTTGCCTTGACACCACAACAAG.TGCAGCAAATCAG 549 I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I 1 1 I I I I I . 1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I * I I I I I I I I I I I I 280 AAACCTGTTTTGCATTTGCCTTGACACCACAACAAGTNGCAGCAAATCAG 329 550 TAGTTCCATGGATATTTCTGGGACCAAATGTGACTTCACAGTACAGGTCC 599 I I I I I 1 I I I I I I I I I I I I 1 I I I I I I I I I I I I 1 I I I I I I I I I I 330 TAGTTCCATGGGTATTTCTGGG 351 The deduced amino acid sequence of 1VBP2 was used to search the GenBank data base for other polynucleotides encoding homologous (i.e., related sequence) polypeptides. No significant homologies were found. p53UBC One poεitive clone, deεignated clone 75A (p53UBC) waε iεolated. p53UBC binds to a carboxy-terminal portion of human p53 (aa72 to aa393) . The p53UBC polypeptide binds both wild-type and mutant p53 polypeptides, with a slight preference for binding to wild-type p53 (described supra) , as determined in a yeast two-hybrid system. The p53UBC clone was sequenced and the nucleotide sequence and deduced amino acid sequences are shown in Fig. 2. Sequence analysis of p53UBC revealed that the encoded polypeptide sequence has significant homology to certain ubiquitin conjugating enzymes. Ubiquitin conjugating enzymes have been reported to be involved in mediating degradation of certain intracellular proteins (Chen et al. (1993) Cell 74: 357) . Although the present invention has been described in some detail by way of illustration for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the claims.

Claims: Claimε 1. An iεolated WBPl polypeptide compriεing a polypeptide sequence of at leaεt 25 conεecutive amino acidε which is substantially identical to a polypeptide sequence shown in Figs. 1A-1D. 2. An isolated WBPl polypeptide of claim 1 which is substantially identical to the polypeptide sequence: 1 LLGPKHELEL PHLTSALHPV HPDIKLQKLP FYDL DELIK PTSLASDNSQ 51 RFRETCFAFA LTPQQVQQIS SSMDISGTKC DFTVQVQLRF CLSETSCPQE 101 DHFPPNLCVK VNTKPCSLPG YLPPTKNGVE PKRPSRPINI TSLVRLSTTV 151 PNTIWSWTA EIGRNYSMAV YLVKQLSSTV LLQRLRAKGI RNPDHSRA I 201 KEKLTADPDS EIATTSLRVS LLCPLGKMRL IPCRALTCS HLQCFDATLY 251 IQMNEKKPTW VCPVCDKKAP YEHLIIDGLF MEILKYCTDC DEIQFKEDGT 301 APMRSKKEV QEVSASYNGV DGCLSSTLEH QVASHHQSSN KNKKVEVIDL 351 TIDSSSDEEE EEPSAKRTCP SLSPTSPLNN KGI SLPHQA SPVSRTPSLP 401 AVDTSYINTS LIQDYRHPFH MTPMPYDLQG LDFFPFLSGD NQHYNTSLLA 451 AAAAAVSDDQ DLLHSSRFFP YTSSQMFLDQ SAGGSTSLP TTNGSSSGSN 501 SSLVSSNSLR ESHSHTVTNR SSTDTASIFG IIPDIIS D 3. An isolated WBPl polypeptide of claim 1 which comprises the p53-binding polypeptide sequence: -ELPHLTSALHPVHPDIKLQKLPFYDLLDELIKPTSLASDNSQRFRETCFAFALTPQQVQQ ISSSMDISGTKCDFTVQVQLRFCLSETSCPQEDHFPPNLCVKVNTKPCSLPGYLPPTKNG VEPKRPSRPINITSLVRLSTTVPNTIWSWTA-. 4. An isolated WBPl polypeptide of claim 3 which compriseε the 597 amino acid polypeptide sequence: 1 MKIKELYRRR FPQKIMTPAD LSIP VHSSP MPATLSPSTI PQLTYDGHPA 51 SSPLLPVSLL GPKHELELPH LTSALHPVHP DIKLQKLPFY DLLDELIKPT 101 SLASDNSQRF RETCFAFALT PQQVQQISSS MDISGTKCDF TVQVQLRFCL 151 SETSCPQEDH FPPNLCVKVN TKPCSLPGYL PPTKNGVEPK RPSRPINITS 201 LVRLSTTVPN TIWSWTAEI GRNYSMAVYL VKQLSSTV L QRLRAKGIRN 251 PDHSRALIKE KLTADPDSEI ATTSLRVSLL CP GKMRLTI PCRALTCSHL 301 QCFDATLYIQ MNEKKPTWVC PVCDKKAPYE HLIIDGLFME ILKYCTDCDE 351 IQFKEDGTWA PMRSKKEVQE VSASYNGVDG CLSSTLEHQV ASHHQSSNKN 401 KKVEVIDLTI DSSSDEEEEE PSAKRTCPSL SPTSP NNKG ILSLPHQASP 451 VSRTPSLPAV DTSYINTSLI QDYRHPFHMT PMPYD QGLD FFPFLSGDNQ 501 HYNTSLLAAA AAAVSDDQDL LHSSRFFPYT SSQMFLDQLS AGGSTSLPTT 551 NGSSSGSNSS LVSSNSLRES HSHTVTNRSS TDTASIFGII PDIISLD. 5. An isolated WBPl polypeptide of claim 4 which consists esεentially of the 597 amino acid polypeptide sequence: 1 MKIKELYRRR FPQKIMTPAD LSIPNVHSSP MPATLSPSTI PQLTYDGHPA 51 SSPLLPVSLL GPKHELELPH LTSALHPVHP DIKLQKLPFY DLLDELIKPT 101 SLASDNSQRF RETCFAFALT PQQVQQISSS MDISGTKCDF TVQVQLRFCL 151 SETSCPQEDH FPPNLCVKVN TKPCSLPGYL PPTKNGVEPK RPSRPINITS 201 LVRLSTTVPN TIWSWTAEI GRNYSMAVYL VKQLSSTVLL QRLRAKGIRN 251 PDHSRALIKE KLTADPDSEI ATTSLRVSLL CPLGKMRLTI PCRALTCSHL 301 QCFDATLYIQ MNEKKPTWVC PVCDKKAPYE HLIIDGLFME ILKYCTDCDE 351 IQFKEDGT A PMRSKKEVQE VSASYNGVDG CLSSTLEHQV ASHHQSSNKN 401 KKVEVIDLTI DSSSDEEEEE PSAKRTCPSL SPTSPLNNKG ILSLPHQASP 451 VSRTPSLPAV DTSYINTSLI QDYRHPFHMT PMPYDLQGLD FFPFLSGDNQ 501 HYNTSLLAAA AAAVSDDQDL LHSSRFFPYT SSQMFLDQLS AGGSTSLPTT 551 NGSSSGSNSS LVSSNSLRES HSHTVTNRSS TDTASIFGII PDIISLD. 6. An isolated IVBP2 polypeptide of claim 1 which is a naturally-occurring polypeptide sequence in mammals. 7. An iεolated WBPl polypeptide of claim 6 which is a human' WBPl polypeptide. 8. An isolated 1VBP2 polypeptide of claim 7, which comprises at least two of the amino acid sequences shown in Table III. 9. A human WBPl polypeptide in a nonhuman cell or substantially purified from other human proteins, said human WBPl polypeptide comprising the following amino acid sequences, in order from amino-terminal to carboxy-terminal direction with spacer amino acid sequences separating each amino acid sequence are: (1) -ELPHLTSALHP-; (2) -PQQVQQISSSMDISGTKC-; (3) -LLQRLRAKGIRNPDHSRALI-; (4) -WAPMRSKKEVQEVSASYNGV-; (5) -EEPSAKRTCPSLSPTSPLNN-; (6) -TPMPYDLQGLDFFPFLSGD-; (7) -SLVSSNSLRESHSHTVTNR-; (8) -SSTDTASIFGIIPDIISLD-, wherein each spacer amino acid sequence is selected independently and consiεtε of 0-100 amino acidε. 10. 'A human WBPl polypeptide in a nonhuman cell or substantially purified from other human proteins, said FΛBP2 polypeptide comprising the polypeptide sequence: 1 LLGPKHELEL PHLTSALHPV HPDIKLQKLP FYDLLDELIK PTSLASDNSQ 51 RFRETCFAFA LTPQQVQQIS SSMDISGTKC DFTVQVQLRF CLSETSCPQE 101 DHFPPNLCVK VNTKPCSLPG YLPPTKNGVE PKRPSRPINI TSLVRLSTTV 151 PNTIWSWTA EIGRNYSMAV YLVKQLSSTV LLQRLRAKGI RNPDHSRALI 201 KEKLTADPDS EIATTSLRVS LLCPLGKMRL TIPCRALTCS HLQCFDATLY 251 IQMNEKKPTW VCPVCDKKAP YEHLIIDGLF MEILKYCTDC D^igF^SDGT 301 WAPMRSKKEV QEVSASYNGV DGCLSSTLEH QVASHHQΣSN f X ~ _~Tπ_ 351 TIDSSSDEEE EEPSAKRTCP SLSPTSPLNN KGILSLPHi . l ' .ΛΓVSJ.., "5 401 AVDTSYINTS LIQDYRHPFH MTPMPYDLQG LDFFPFLSGD NQRYNTSLL 451 AAAAAVSDDQ DLLHSSRFFP YTSSQMFLDQ LSAGGSTSLP TTNGSSSGSN 501 SSLVSSNSLR ESHSHTVTNR SSTDTASIFG IIPDIISLD. 11. A human JVBP2 polypeptide of claim 10 in a nonhuman cell or subεtantially purified from other human proteinε, εaid WBPl polypeptide conεiεting eεεentially of the polypeptide εequence: 1 MKIKELYRRR FPQKIMTPAD LSIPNVHSSP MPATLSPSTI PQLTYDGHPA 51 SSPLLPVSLL GPKHELELPH LTSALHPVHP DIKLQKLPFY DLLDELIKPT 101 SLASDNSQRF RETCFAFALT PQQVQQISSS MDISGTKCDF TVQVQLRFCL 151 SETSCPQEDH FPPNLCVKVN TKPCSLPGYL PPTKNGVEPK RPSRPINITS 201 LVRLSTTVPN TIWSWTAEI GRNYSMAVYL VKQLSSTVLL QRLRAKGIRN 251 PDHSRALIKE KLTADPDSEI ATTSLRVSLL CPLGKMRLTI PCRALTCSHL 301 QCFDATLYIQ MNEKKPT VC PVCDKKAPYE HLIIDGLFME ILKYCTDCDE 351 IQFKEDGTWA PMRSKKEVQE VSASYNGVDG CLSSTLEHQV ASHHQSSNKN 401 KKVEVIDLTI DSSSDEEEEE PSAKRTCPSL SPTSPLNNKG ILSLPHQASP 451 VSRTPSLPAV DTSYINTSLI QDYRHPFHMT PMPYDLQGLD FFPFLSGDNQ 501 HYNTSLLAAA AAAVSDDQDL LHSSRFFPYT SSQMFLDQLS AGGSTSLPTT 551 NGSSSGSNSS LVSSNSLRES HSHTVTNRSS TDTASIFGII PDIISLD. 12. A human WBPl polypeptide of claim 10 fuεed in polypeptide linkage to a heterologouε polypeptide sequence. 13. A human JVBP2 polypeptide of claim 10, wherein said heterologouε polypeptide εequence is a GAL4 activation domain sequence or a GAL4 DNA-binding domain. 14. An isolated polynucleotide encoding a JVBP2 polypeptide of claim 1. 15. An isolated polynucleotide of claim 14, comprising at least two polynucleotide sequences of Table I. 16. An isolated polynucleotide of claim 15, wherein said polynucleotide compriseε five sequences independently selected from the group of sequences consisting of: 5 -GACTTGTCCATCCCCAACGTACATTCAAGTCCTATGC-3 ' ; 5 -CTTCAAAAATTACCATTTTATGATTTACTGGATGAACT-3 ' ; 5 -CATCAGACAACAGTCAGCGCTTTCGAGAAACCTGTTTTGC-3 ' ; 5 -CACAACAAGTGCAGCAAATCAGTAGTTCCATGGATA-3 • ; 5 -GTACAGGTCCAGTTAAGGTTTTGTTTATCAGAAACCAGTTG-3 ' ; 5 -TGAAAGTGAATACAAAACCTTGCAGCCTTCCAGG-3 ' ; 5 -CCACCTACAAAAAATGGCGTGGAACCAAAGCGACCCAGCCGAC-3 ' ; 5 -GACTGTCCACAACAGTACCAAACACGATTGTTG-3 ' ; 5 -GGAAGAAACTATTCCATGGCAGTATATCTTGTAAAACAGT-3 ' ; 5 -CAGAGGTTACGAGCAAAGGGAATAAGGAATCCGGATCATTCTAGAG-3 » ; 5 -GGATCCAGACAGTGAAATAGCTACAACCAGCCTAAG-3 ' ; 5 -CTTGGTAAAATGCGGCTGACAATTCCGTGTCGGGCCCTTAC-3 ' ; 5 -CATCTACAATGTTTTGACGCAACTCTTTACATTCAGATG-3 ' ; 5 -GTCCTGTCTGTGATAAGAAGGCTCCATATGAACACC-3 ' ; 5 -TCCTAAAGTACTGTACAGACTGTGATGAAATACAATTTAAGGAGGATG-3 • 5 -GGAAGTACAGGAAGTTTCTGCCTCTTACAATGGAGTC-3 ' ; 5 -CTTGAGCTCCACATTGGAGCATCAGGTAGCGTCTCACCAC-3 • ; 5 -AGTGATTGACCTAACCATAGACAGTTCATCTGATGAAGAGGA-3 • ; 5 -CCAAGAGGACCTGTCCTTCCCTATCTCCCACATCACCACT-3 ' ; 5 -CTTCCACATCAAGCATCTCCAGTATCCCGCACCCCAAGCCTTC-3 ' ; 5 -TAATACCTCCCTCATCCAAGACTATAGGCATCCTTTCC-3 ' ; 5 -CCATGCCTTACGACTTACAAGGATTAGATTTCTTTCCTTTCTTATCA-3 ' ; 5 -ACAACACCTCCTTGCTTGCCGCTGCAGCAGCAGCAGTTTCAGAT-3 ' ; 5 -CTACACTCGTCTCGGTTTTTCCCGTATACCTCCTCACAG-3 ' ; 5 -GGAGGCAGTACTTCTCTGCCAACCACCAATGGAAGC-3 ' ; 5 -GGTTTCTTCCAACAGCCTAAGGGAAAGCCATAGCCACAC-3 ' ; 5 -CGGACACGGCATCCATCTTTGGCATCATACCAGACATTAT-3 ■ ; 5 -GCTGCTCCCATCCCCACCCCAGATCGAATGAACTTGGCAGA-3 ' ; 5 -GTGCTCTGTTTTACCTTACTCTGTTTAGAAAAGTATACAAGCGTG-3 • ; 5 -GAAATGTACAGAGAACAAAACTATATTTTCAGTT-3 and 5 -CTTTTGTATATAAATCTAAGACTGCCTGTGTGATAAAACACTTG-3 ' 17. An isolated polynucleotide of claim 15, wherein said polynucleotide compriseε the sequence: GGCACGAGGCGGACAGTGCGGAACTAAAGCAAATGGTTATGAGCCTTAGAGTTTCTGAACTCCAA GTACTGTTGGGCTACGCGGGAGAAACAAGCACGGACGCAAACACGAACTTCTCACAAAAGCCCTG CATTTGCTAAAGGCTGGCTGTAGTCCTGCTGTGCAAATGAAAATTAAGGAACTCTATAGGCGGCG GTTCCCACAGAAAATCATGACGCCTGCAGACTTGTCCATCCCCAACGTACATTCAAGTCCTATGC CAGCAACTTTGTCTCCATCTACCATTCCACAACTCACTTACGATGGTCACCCTGCATCATCGCCA TTACTCCCTGTTTCTCTTCTGGGACCTAAACATGAACTGGAACTCCCACATCTTACATCAGCTCT TCACCCAGTCCATCCGGATATAAAACTTCAAAAATTACCATTTTATGATTTACTGGATGAACTGA TAAAACCCACCAGTCTAGCATCAGACAACAGTCAGCGCTTTCGAGAAACCTGTTTTGCATTTGCC TTGACACCACAACAAGTGCAGCAAATCAGTAGTTCCATGGATATTTCTGGGACCAAATGTGACTT CACAGTACAGGTCCAGTTAAGGTTTTGTTTATCAGAAACCAGTTGTCCACAAGAAGATCACTTCC CACCCAATCTTTGTGTGAAAGTGAATACAAAACCTTGCAGCCTTCCAGGTTACCTTCCACCTACA AAAAATGGCGTGGAACCAAAGCGACCCAGCCGACCAATTAATATCACCTCACTTGTCCGACTGTC CACAACAGTACCAAACACGATTGTTGTTTCTTGGACTGCAGAAATTGGAAGAAACTATTCCATGG CAGTATATCTTGTAAAACAGTTGTCCTCAACAGTTCTTCTTCAGAGGTTACGAGCAAAGGGAATA AGGAATCCGGATCATTCTAGAGCTTTAATTAAAGAGAAGTTGACTGCGGATCCAGACAGTGAAAT AGCTACAACCAGCCTAAGGGTTTCTCTACTATGTCCACTTGGTAAAATGCGGCTGACAATTCCGT GTCGGGCCCTTACATGTTCTCATCTACAATGTTTTGACGCAACTCTTTACATTCAGATGAATGAG AAAAAACCAACCTGGGTTTGTCCTGTCTGTGATAAGAAGGCTCCATATGAACACCTTATTATTGA TGGCTTGTTTATGGAAATCCTAAAGTACTGTACAGACTGTGATGAAATACAATTTAAGGAGGATG GCACTTGGGCACCGATGAGATCAAAAAAGGAAGTACAGGAAGTTTCTGCCTCTTACAATGGAGTC GATGGATGCTTGAGCTCCACATTGGAGCATCAGGTAGCGTCTCACCACCAGTCCTCAAATAAAAA CAAGAAAGTAGAAGTGATTGACCTAACCATAGACAGTTCATCTGATGAAGAGGAAGAAGAGCCAT CTGCCAAGAGGACCTGTCCTTCCCTATCTCCCACATCACCACTAAATAATAAAGGCATTTTAAGT CTTCCACATCAAGCATCTCCAGTATCCCGCACCCCAAGCCTTCCTGCTGTAGACACAAGCTACAT TAATACCTCCCTCATCCAAGACTATAGGCATCCTTTCCACATGACACCCATGCCTTACGACTTAC AAGGATTAGATTTCTTTCCTTTCTTATCAGGAGACAATCAGCATTACAACACCTCCTTGCTTGCC GCTGCAGCAGCAGCAGTTTCAGATGATCAAGACCTCCTACACTCGTCTCGGTTTTTCCCGTATAC CTCCTCACAGATGTTTCTTGATCAGTTAAGTGCAGGAGGCAGTACTTCTCTGCCAACCACCAATG GAAGCAGTAGTGGCAGTAACAGCAGCCTGGTTTCTTCCAACAGCCTAAGGGAAAGCCATAGCCAC ACCGTCACAAACAGGAGCAGCACGGACACGGCATCCATCTTTGGCATCATACCAGACATTATTTC ATTGGACTGATTCCCAGGCCCTGCTGCTCCCATCCCCACCCCAGATCGAATGAACTTGGCAGAAA GAAGAGAACTTTGTGCTCTGTTTTACCTTACTCTGTTTAGAAAAGTATACAAGCGTGTTTTTTTT CCTTTTTTTAGGGAAAAAATTAAAAGAAATGTACAGAGAACAAAACTATATTTTCAGTTTTACTT TTGTATATAAATCTAAGACTGCCTGTGTGATAAAACACTTGTTTAAA 18. An isolated p53UBC polypeptide comprising a polypeptide sequence of at least 25 consecutive amino acids which is subεtantially identical to a polypeptide sequence shown in Fig. 2. 19. An isolated p53UBC polypeptide of claim 18 which is is substantially identical to the polypeptide sequence: 1 RGTLNMSGIA LSRLAQERKA WRKDHPFGFV AVPTKNPDGT MNLMNWESAI 51 PGKKGTPWEG GLFKLRMLFK DDYPSSPPKC KFEPPLFHPN VYFGTVCLSI 101 LEEDKDWRPA ITIKQILLGI QELLNEPNIQ DPAQAEAYTI YCQNRVEYEK 151 RVRAQAKNLR PHKQRPCGIV RRKGLVWQEL VYNIFANLKL LHTMTSHLGG 201 LGGRHLPLPP RVCGLDSLNC PFPYRVSSSV FCIFDCYVKL AFILILMSVF 251 QLL. 20. An isolated p53UBC polypeptide of claim 18 which is a naturally-occurring polypeptide εequence in mammalε. 21. An iso " v..ed p53UBC polypeptide of claim 20 which iε a human p53UBC polypeptide. 22. An isolated p53UBC polypeptide of claim 20, which comprises at least two of the amino acid sequences shown in Table IV. 23. A human p53UBC polypeptide in a nonhuman cell or substantially purified from other human proteins, said human p53UBC polypeptide comprising the following amino acid sequenceε, in order from amino-terminal to carboxy-terminal direction with spacer amino acid sequences separating each amino acid sequence are: -RKAWRKDHPFGFVAVPTKNP-; -NIQDPAQAEAYTIYCQNRVEYE-; -GLVWQELVYNIFANLKLLHT-; -GLDSLNCPFPYRVSSSVFCI-; and -KLAFILILMSVFQL-. 24. An isolated polynucleotide encoding a p53UBC polypeptide of claim 18, claim 19, or claim 23. 25. An isolated polynucleotide of claim 24, comprising at least two polynucleotide sequences of Table II. 26. An isolated polynucleotide of claim 25, wherein said polynucleotide encodes the following polypeptide sequence: 1 RGTLNMSGIA LSRLAQERKA WRKDHPFGFV AVPTKNPDGT MNLMNWESAI 51 PGKKGTPWEG GLFKLRMLFK DDYPSSPPKC KFEPPLFHPN VYFGTVCLSI 101 LEEDKDWRPA ITIKQILLGI QELLNEPNIQ DPAQAEAYTI YCQNRVEYEK 151 RVRAQAKNLR PHKQRPCGIV RRKGLVWQEL VYNIFANLKL LHTMTSHLGG 201 LGGRHLPLPP RVCGLDSLNC PFPYRVSSSV FCIFDCYVKL AFILILMSVF 251 QLL. 27. The isolated polynucleotide of claim 26, wherein said polynucleotide is present in a yeast cell. 28. An isolated polynucleotide comprising at leaεt two εequenceε shown in Table II. 29. An isolated polynucleotide comprising the sequence: CGAGGGACTTTGAACATGTCGGGGATCGCCCTCAGCAGACTCGCCCAGGAGAGGAAAGCATGGAGGAAAGACCAC CCATTTGGTTTCGTGGCTGTCCCAACAAAAAATCCCGATGGCACGATGAACCTCATGAACTGGGAGAGCGCCATT CCAGGAAAGAAAGGGACTCCGTGGGAAGGAGGCTTGTTTAAACTACGGATGCTTTTCAAAGATGATTATCCATCT TCGCCACCAAAATGTAAATTCGAACCACCATTATTTCACCCGAATGTGTACTTCGGGACAGTGTGCCTGTCCATC TTAGAGGAGGACAAGGACTGGAGGCCAGCCATCACAATCAAACAGATCCTATTAGGAATACAGGAACTTCTAAAT GAACCAAATATCCAAGACCCAGCTCAAGCAGAGGCCTACACGATTTACTGCCAAAACAGAGTGGAGTACGAGAAA AGGGTCCGAGCTCAAGCCAAGAATTTGCGCCCTCATAAGCAGCGACCTTGTGGCATCGTCAGAAGGAAGGGATTG GTTTGGCAAGAACTTGTTTACAACATTTTTGCAAATCTAAAGTTGCTCCATACAATGACTAGTCACCTGGGGGGG TTGGGCGGGCGCCATCTTCCATTGCCGCCGCGGGTGTGCGGTCTCGATTCGCTGAATTGCCCGTTTCCATACAGG GTCTCTTCTTCGGTCTTTTGTATTTTTGATTGTTATGTAAAACTCGCTTTTATTTTAATATTGATGTCAGTATTT CAACTGCTGTAAAATTATAAACTTTTATACTTGGGTAAGTCCCCCAGGGCGAGTTCCTCGCTCTGGGATGCAGGC ATGCTTCTCACCGTGCAGAGCTGCACTTGGCCTCAGCTGGCTGTATGGAAATGCACCCTCCCTCCTGCGCTCCTC TCTAGAACCTTCTAGAACCTGGGCTGTGCTGCTTTTGAGCCTCAGACCCCAGGGCAGCATCTCGGTTCTGCGCCA CTTCCTTTGTGTTTATATGGCGTTTTGTCTGTGTTGCTGTTTAGAGTAAATAAACTGTTTATATAAAAAAAAAAA AAAAAAAAGTCCGAATTGCGCACGAGGCGCTATCACCACCTCAGTTATACTCTTATTCCTAGATATTTGGGACAT AAGAACCAAAATCTAAAAATTAAGAGGTTTCCTCCTCAAATACAGAATAAAAGCTGCTATGCCTGAGGCATACAG GGCTTTGTTGGTCCGGCACATCATATTTTACTATTTGTTTGAGGTATTTGCCGAATCTTGTTAATAACAGTGAAT AATCTTGTCTTTTTATTTTAATATACACAGCACAGTAAAGAAAAGCATTAATTGCGTTTTGTGGACTTTACAACA TGGCTAAACCCATATTCTTAGATTTGGACATAGATAGATGCTTAGTAAATACTAAATTGAAATGAATTAGGCCAG AGGAGATCAGACATAGGAATTTAAAGTTAGTCTTGAGAGAAACTTAGGTAAAAAGAAAAACAAAATTAAAGGAGG ACTGTGTGTGAGAGTTGAAAGATATAAGTTCCAGAATGTTGTGGCAGGACAGTGAAATCTTCTGGTTCCTAAAGA CGGAGGAGACTCTCTCCCAGCACCTGACTTCCACCCTCCCACTACTGCCAGACCTTTGCCTGGGCTGTTCCTAGC CTGGAGCACTGTCCCCCGTCTCGATCCTGCCTTCCCCTGAAACCCCTGCAGGGGCTGCCCTCTTTTGGCCTCCCA CTGTGTCCCTTCTCTCATGTGCATTAGATCTCAGCCTGGCCTTGAATGTCTCTTTCTCACCAGTACCTTGCACAG TAAACATTCAAACTTACTGTGAATTCATCTGAAAAAAAAA. 30. An isolated polynucleotide consiεting eεsentially of the sequence: CGAGGGACTTTGAACATGTCGGGGATCGCCCTCAGCAGACTCGCCCAGGAGAGGAAAGCATGGAGGAAAGACCAC CCATTTGGTTTCGTGGCTGTCCCAACAAAAAATCCCGATGGCACGATGAACCTCATGAACTGGGAGAGCGCCATT CCAGGAAAGAAAGGGACTCCGTGGGAAGGAGGCTTGTTTAAACTACGGATGCTTTTCAAAGATGATTATCCATCT TCGCCACCAAAATGTAAATTCGAACCACCATTATTTCACCCGAATGTGTACTTCGGGACAGTGTGCCTGTCCATC TTAGAGGAGGACAAGGACTGGAGGCCAGCCATCACAATCAAACAGATCCTATTAGGAATACAGGAACTTCTAAAT GAACCAAATATCCAAGACCCAGCTCAAGCAGAGGCCTACACGATTTACTGCCAAAACAGAGTGGAGTACGAGAAA AGGGTCCGAGCTCAAGCCAAGAATTTGCGCCCTCATAAGCAGCGACCTTGTGGCATCGTCAGAAGGAAGGGATTG GTTTGGCAAGAACTTGTTTACAACATTTTTGCAAATCTAAAGTTGCTCCATACAATGACTAGTCACCTGGGGGGG TTGGGCGGGCGCCATCTTCCATTGCCGCCGCGGGTGTGCGGTCTCGATTCGCTGAATTGCCCGTTTCCATACAGG GTCTCTTCTTCGGTCTTTTGTATTTTTGATTGTTATGTAAAACTCGCTTTTATTTTAATATTGATGTCAGTATTT CAACTGCTGTAAAATTATAAACTTTTATACTTGGGTAAGTCCCCCAGGGCGAGTTCCTCGCTCTGGGATGCAGGC ATGCTTCTCACCGTGCAGAGCTGCACTTGGCCTCAGCTGGCTGTATGGAAATGCACCCTCCCTCCTGCGCTCCTC TCTAGAACCTTCTAGAACCTGGGCTGTGCTGCTTTTGAGCCTCAGACCCCAGGGCAGCATCTCGGTTCTGCGCCA CTTCCTTTGTGTTTATATGGCGTTTTGTCTGTGTTGCTGTTTAGAGTAAATAAACTGTTTATATAAAAAAAAAAA AAAAAAAAGTCCGAATTGCGCACGAGGCGCTATCACCACCTCAGTTATACTCTTATTCCTAGATATTTGGGACAT AAGAACCAAAATCTAAAAATTAAGAGGTTTCCTCCTCAAATACAGAATAAAAGCTGCTATGCCTGAGGCATACAG GGCTTTGTTGGTCCGGCACATCATATTTTACTATTTGTTTGAGGTATTTGCCGAATCTTGTTAATAACAGTGAAT AATCTTGTCTTTTTATTTTAATATACACAGCACAGTAAAGAAAAGCATTAATTGCGTTTTGTGGACTTTACAACA TGGCTAAACCCATATTCTTAGATTTGGACATAGATAGATGCTTAGTAAATACTAAATTGAAATGAATTAGGCCAG AGGAGATCAGACATAGGAATTTAAAGTTAGTCTTGAGAGAAACTTAGGTAAAAAGAAAAACAAAATTAAAGGAGG ACTGTGTGTGAGAGTTGAAAGATATAAGTTCCAGAATGTTGTGGCAGGACAGTGAAATCTTCTGGTTCCTAAAGA CGGAGGAGACTCTCTCCCAGCACCTGACTTCCACCCTCCCACTACTGCCAGACCTTTGCCTGGGCTGTTCCTAGC CTGGAGCACTGTCCCCCGTCTCGATCCTGCCTTCCCCTGAAACCCCTGCAGGGGCTGCCCTCTTTTGGCCTCCCA CTGTGTCCCTTCTCTCATGTGCATTAGATCTCAGCCTGGCCTTGAATGTCTCTTTCTCACCAGTACCTTGCACAG TAAACATTCAAACTTACTGTGAATTCATCTGAAAAAAAAA. 31. An protein complex compriεing a polypeptide of claim 5 or claim 19 and a human p53 polypeptide, wherein said complex is present in a non-human cell. 32. An isolated host cell comprising a recombinant polynucleotide encoding a polypeptide of claim 14. 33. A non-mammalian host cell comprising a mammalian p53 polypeptide and a mammalian p53UBC or WBPl polypeptide. 34. A composition compriεing polynucleotide εequences encoding (1) a first hybrid polypeptide comprising a p53 polypeptide and an activator domain of a transcriptional activator protein, (2) a second hybrid polypeptide comprising a p53UBC or WBPl polypeptide and a DNA-binding domain of said transcriptional activator protein, and (3) a reporter polynucleotide linked to a transcriptional regulatory element whose tranεcriptional activity iε dependent upon the preεence or abεence of a heterodimer compriεed of the firεt and second hybrid polypeptide. 35. A method for identifying agents that inhibit binding Of a p53 polypeptide to a p53UBC or JVBP2 polypeptide to form heteromultimers, said method comprising: performing a heterodimerization assay which includes a p53 polypeptide species comprising a binding domain with a p53UBC or 1VBP2 polypeptide specieε compriεing a binding domain and an agent under suitable binding conditions; determining whether the agent inhibitε heterodimerization of the p53 polypeptide to the p53UBC or WBPl polypeptide; identifying agentε which inhibit said heterodimerization as candidate p53 modulating agents and candidate pharmaceuticals.

Inventors: BISCHOFF JAMES R, WU LELIA, BISCHOFF, JAMES, R., WU, LELIA
Applicants: BISCHOFF JAMES R, ONYX PHARMACEUTICALS, WU LELIA, BISCHOFF, JAMES, R., WU, LELIA
Application year: 1994
Main classification: C12N15
IPC codes: A61K31, A61K38, A61K49, A61P1, A61P9, A61P25, A61P31, A61P35, C07H21, C07K14, C12N1, C12N5, C12N15, G01N33